United States

Environmental Protection

Agency

Air and Radiation EPA420-R-00-012

August 2000

Effectiveness of OBD II

Evaporative Emission

Monitors - 30 Vehicle

Study

 Printed on Recycled Paper
EPA420-R-00-012

August 2000

Effectiveness of OBD II Evaporative Emission

Monitors - 30 Vehicle Study

Martin Reineman

Transportation and Regional Programs Division

Office of Transportation and Air Quality

U.S. Environmental Protection Agency

NOTICE

This technical report does not necessarily represent final EPA decisions or positions.

It is intended to present technical analysis of issues using data that are currently available.

The purpose in the release of such reports is to facilitate the exchange of

technical information and to inform the public of technical developments which

may form the basis for a final EPA decision, position, or regulatory action.




IV. Test Protocol

Induced Failure Modes

Based on EPA’s inspection of evaporative emission DTCs and their causes, it was suspected

that the majority of evaporative emission failures in OBD vehicles can be attributed to loose gas

caps, but EPA does not, at present, have a source of published data to verify this assertion. 

Rather, it is based on undocumented experience gained during recruitment of OBD II vehicles

for test programs at the EPA National Vehicle Fuels and Emission Laboratory (NVFEL) and

discussions with I/M and OBD experts from domestic vehicle manufacturers. Rather than

recruit only loose gas cap vehicles as the primary source of “failed” vehicles, it was decided to

procure rental vehicles and induce a variety of failure modes which could occur in the OBD II inuse fleet. Inducing failures was thought to be necessary given that evaporative emission

failures are more age than mileage related, and we did not expect to find a variety of real world

failure modes.

Table A-2 in the Appendix describes the induced faults, the resulting DTCs, the drive cycles

required to satisfy the readiness criteria for both “failure” and “repair” sequences, and a

comment column for more detail on specific vehicle test issues. Although only one set of drive

cycles are listed in Table A-2, both induced failure and post-repair sequences used the same

drive cycles to satisfy readiness criteria and exercise the OBD system. The induced failures in

the 30 vehicle sample included the following:




































Veh Model Disp Odom Tank Vol Tank Evap 

No. Yr Make Model liters miles Engine Family Evap Family gal Material Std 

140 99 Honda Civic 2.0 7,576 XHNXV01.6CA3 XHNXR0099AAD 16.0 Metal ORVR 

141 96 Ford Explorer 4.0 116,730 TFM4.028GKFK TFM1120AYMED 21.0 Metal Enhance142 99 Chevrolet Tahoe 5.7 9,440 XGMXA05.7186 XGMXE0111911 30.0 Plastic Enhance

143 98 Toyota Camry 2.2 21,197 WTYXV02.2XBA WTYXR0135AK1 18.5 Metal ORVR 144 99 Chevrolet Monte Carlo 3.1 7,978 XGMXV03.4041 XGMXE0095904 16.6 Metal Enhance145 98 Nissan Altima 2.4 35,574 WSNXV02.4A3A WNSXR0110RCA 15.8 Plastic ORVR 

146 99 Mitsubishi Mirage 1.5 9,442 XMTXV01.5GFD XMTXR0140A1A 12.4 Metal ORVR 147 97 Ford Taurus 3.0 49,443 VFM3.0V8GKEK VFM1115AYMEB 16.0 Metal Enhance148 99 Toyota Pickup 2.4 78,042 XTYXT02.4BBH XTYXE0095AE0 15.1 Metal Enhance149 99 Chevrolet Cavalier 2.2 16,124 XGMXV02.2021 XGMXR0124912 15.0 Metal ORVR 150 98 Mazda 626 LX 2.0 21,378 WTKXV02.0VBA WTKXR0125BFA 16.9 Metal ORVR 151 98 Chevrolet Lumina 3.1 31,859 WGMXV03.1041 WGMXE0095904 16.6 Metal Enhance

152 99 Ford Ranger 3.0 5,259 XFMXT03.32DC XFMXE0155FBE 19.5 Plastic Enhance153 99 Honda Accord LX 2.3 12,950 XHNXV02.3PA3 XHNXR0130AAA 17.1 Metal ORVR 154 99 Nissan Sentra 1.6 29,362 XNSXV01.6A1A XNSXR0085RCA 13.3 Metal ORVR 

Vehicle Descriptions

Table A-1
155 99 Mercury Tracer 2.0 12,782 XFMXV02.0VBA XFMXR0080BAE 12.8 Metal ORVR 

156 99 Toyota Sienna 3.0 30,611 XTYXT03.0XBP XTYXE0115AE1 21.0 Metal Enhance182 98 Mazda 626 2.0 32,854 WTKXV02.0VBA WTKXR0125BFA 16.9 Metal ORVR 183 00 Nissan Maxima 3.0 6,742 YNSZV03.0A6A YNSXR0110RCC 19.5 Metal ORVR 

184 99 Mercury Gr.Marquis 4.6 25,678 XFMXV04.6VBE XFMXR0115BAE 19.0 Metal ORVR 185 98 Chevrolet S-10 4.3 14,745 WGMXT04.3183 WGMXE009504 18.5 Metal Enhance

186 98 Ford F-150 4.6 73,787 WFMXT04.6BAA WFMXE0160BAE 24.5 Metal Enhance187 99 Infinity QX4 3.3 27,453 XNSXT03.3A5B XNSXE0110MBA 21.2 Metal Enhance188 99 Honda Accord 2.3 11,636 XHNXV02.3PA3 XHNXR0130AAA 17.2 Metal ORVR 189 00 Toyota Corolla 1.8 7,592 YTYXV01.8FFA YTYXR0115AK1 13.2 Metal ORVR 190 99 Toyota Tacoma 2.4 41,142 XTYXT02.4BBH XTYXE0095AE0 15.2 Metal Enhance191 96 Isuzu Rodeo 3.2 77,640 TSZ3.22JGKEK TSZ1089AYME0 21.9 Metal Enhance192 98 Ford Windstar 3.8 68,892 WFMXT03.8ABA WFMXE0140BBE 20.0 Plastic Enhance193 98 Chevrolet Malibu 3.1 29,871 WGMXV03.1041 WGMXR0124912 15.0 Metal ORVR 194 99 Pontiac Grand Am 2.4 21,666 XGMXV02.4024 XGMXR0124912 15.0 Metal ORVR 
Veh Failure/ Test Test Test SHED Test 

No. Repair No. HC CH4 CO NOx CO2 MPG No. Grams gr/mi No. Grams No. No. G

140R F 21060 0.03 0.03 0.6 0.04 273 32.4 21064 220.86 12.81 3057 3.91 15 3058 

R 21306 0.04 0.03 1.1 0.03 282 31.3 21256 0.28 0.02 3085 0.10 15 3087 

12.80 3.81 

141E F 21173 0.15 0.11 1.1 0.28 441 20.1 21175 289.62 16.75 3078 2.72 15 3079 

R 21246 0.14 0.10 1.8 0.49 504 17.5 21248 0.57 0.03 3093 0.25 12 3094 

16.72 2.47 

142E F 21571 0.10 0.09 1.7 0.26 618 14.3 21572 46.35 2.69 3097 8.62 15 3098 

R 21618 0.09 0.08 1.8 0.26 621 14.3 21620 0.31 0.02 3104 0.15 14 3105 

2.67 8.47 

143R F 21253 0.14 0.13 1.5 0.24 344 25.6 21255 118.34 6.88 3095 3.62 14 3096 

R 21613 0.13 0.12 1.6 0.17 329 26.8 21615 0.17 0.01 3102 0.09 15 3103 

6.87 3.53 

144E F 21589 0.12 0.11 1.3 0.10 411 21.5 21591 91.67 5.31 3099 54.88 14 3100 

R 21639 0.09 0.08 1.2 0.10 392 22.5 21641 0.24 0.01 3108 0.11 14 3109 

5.30 54.77 

145R F 21677 0.08 0.07 1.3 0.20 355 24.9 21679 78.87 4.57 3112 0.72 15 3113 

R 21743 0.07 0.06 1.4 0.24 347 25.5 21745 0.24 0.01 3123 0.12 12 3124 

4.56 0.60 

146R F 21663 0.15 0.13 1.7 0.19 297 29.7 21665 0.17 0.01 3110 0.07 15 3111 

R 21705 0.14 0.12 1.6 0.15 291 30.3 21707 0.18 0.01 3114 0.07 15 3115 

0.00 0.00 

147E F 21791 0.16 0.14 1.4 0.24 423 20.9 21726 375.91 21.84 3119 23.66 15 3120 

R1 21857 0.25 0.22 2.5 0.43 453 19.4 21859 77.03 4.49 3143 8.28 12 3144 R2 21970 0.20 0.18 1.8 0.29 420 21.0 21972 0.21 0.01 3177 0.07

21.83 23.59

148E F 21888 0.18 0.15 2.4 0.27 358 24.5 21890 1.55 0.09 3150 0.80 14 3151 

R 21993 0.18 0.15 2.1 0.30 363 24.2 21995 0.32 0.02 3183 0.13 11 3185 

0.07 0.67 

149R F 21913 0.07 0.05 1.9 0.04 360 24.5 21914 111.79 6.52 3155 8.96 15 3156 

R 22006 0.09 0.08 1.4 0.04 351 25.1 22008 0.34 0.02 3189 0.30 14 3192 

6.50 8.66 

Table A-3

Not P

Composite Emission Results

Composite Emissions, g/mi Running Loss Hot Soak 3 D
150R F 21996 0.14 0.12 1.2 0.23 362 24.4 21999 95.01 5.53 3184 2.76 14 3186 

R 22137 0.13 0.12 0.9 0.20 349 25.4 22140 0.49 0.03 3230 0.18 11 3232 

151E F 22023 0.15 0.13 2.4 0.13 380 23.1 22026 18.43 1.07 3196 0.98 11 3199 

R 22081 0.14 0.11 2.0 0.15 383 23.0 22083 0.20 0.01 3215 0.06 14 3217 

152E F 22013 0.10 0.09 1.6 0.05 490 18.0 22015 0.34 0.02 3193 0.10 12 3204 

R 22132 0.09 0.09 1.5 0.03 491 18.0 22134 0.13 0.01 3228 0.05 12 3229 

153R F 22072 0.07 0.06 2.2 0.06 343 25.7 22074 212.01 12.29 3210 4.02 12 3214 

R 22166 0.04 0.04 1.6 0.05 350 25.2 22141 164.24 9.51 3231 2.98 11 3239 

154R F 22086 0.10 0.08 2.5 0.07 300 29.3 22088 3.50 0.20 3216 0.14 12 3218 

R 22177 0.10 0.08 2.2 0.08 298 29.5 22179 0.39 0.02 3241 0.12 12 3242 

0.18 0.02 

155R F 22155 0.06 0.05 0.5 0.09 303 29.2 22157 0.28 0.02 3234 0.09 12 3238 

R 22202 0.07 0.07 0.7 0.08 305 29.0 22204 0.31 0.02 3249 0.14 12 3250 

156E F 22121 0.21 0.18 1.4 0.22 434 20.4 22123 45.16 2.62 3223 6.83 14 3226 

R 22182 0.16 0.14 1.3 0.17 390 22.7 22186 0.39 0.02 3244 0.08 15 3247 

2.60 6.75 

182R F1 22262 0.17 0.15 1.1 0.27 346 25.6 22264 128.00 7.42 3255 34.67 14 3256 

R1 22300 0.15 0.14 1.0 0.23 347 25.5 22302 86.43 5.02 3262 11.65 12 3263 

Diag 22456 0.14 0.13 1.2 0.24 353 25.0 22458 0.48 0.03

F2 22518 0.33 0.32 1.5 0.26 354 24.9 22520 46.40 2.69 3301 0.47 12 3301 

R2 22578 0.16 0.14 1.3 0.24 269 23.9 22557 0.44 0.03 3313 0.09 12 3314 

2.66 0.38 

183R F 22368 0.10 0.09 1.1 0.22 412 21.5 22370 16.57 0.96 3277 0.67 11 3278 

R 22438 0.09 0.08 0.9 0.20 412 21.5 22440 0.26 0.02 3288 0.11 12 3289 

0.94 0.56 

184R F 22398 0.33 0.25 6.1 0.06 462 18.8 22400 4.48 0.26 3281 0.55 11 3282 

R 22461 0.12 0.11 1.9 0.06 457 19.3 22463 1.11 0.06 3293 0.11 11 3294 

0.19 0.44 

185E F1 22414 0.16 0.13 1.6 0.25 491 18.0 22416 9.29 0.54 3283 0.12 12 3284 

F2 22571 0.15 0.13 1.6 0.26 499 17.7 22548 8.08 0.47 3310 1.72 12 3311 

R 22469 0.14 0.12 1.6 0.29 480 18.4 22471 0.43 0.03 3295 0.05 12 3296 

0.44 1.67 

186E F 22612 0.19 0.16 2.0 0.35 537 16.4 22614 262.43 15.14 3325 5.40 12 3326 

R 22679 0.18 0.15 1.8 0.37 542 16.3 22681 0.23 0.01 3343 0.04 11 3344 

Not Perf Not P
15.13 5.36 

187E F 22618 0.13 0.12 1.3 0.36 567 15.6 22620 272.47 15.75 3329 11.54 12 3357 

R 22712 0.13 0.12 1.3 0.39 586 15.1 22714 0.43 0.03 3355 0.12 12 3357 

15.75 11.42 

188R F1 22609 0.11 0.18 0.7 0.01 287 30.8 22611 215.72 12.55 3324 21.41 11 3324 

R1 22663 0.06 0.05 1.9 0.04 339 26.0 22635 111.31 6.43 3333 5.34 12 3335 

F2 22694 0.07 0.06 1.5 0.04 335 26.4 22696 191.01 11.05 3348 16.21 12 3351 

R2 22728 11.33 0.66 3365 2.77 11 3366 R3 0.02 0.14

189R F 22733 0.05 0.05 0.7 0.07 282 31.4 22735 42.22 2.44 3368 5.09 12 3370 

R 22763 0.06 0.05 0.5 0.08 285 31.1 22765 0.35 0.02 3388 0.13 12 3389 

2.42 4.96 

190E F 22859 0.20 0.17 3.1 0.18 381 23.0 22831 101.89 0.92 3417 0.92 12 3419 

R 22921 0.13 0.11 1.8 0.16 370 23.8 22923 0.38 0.02 3442 0.14 12 3443 

0.90 0.78 

191E F 22849 0.15 0.14 1.2 0.33 615 14.4 22851 84.87 4.90 3422 1.02 13 3424 

R 22873 0.15 0.13 1.3 0.33 612 14.5 22875 0.81 0.05 3430 0.28 12 3431 

4.86 0.74 

192E F 22860 0.10 0.10 1.1 0.16 467 19.0 22862 4.16 0.24 3427 0.33 13 3428 

R1 22931 0.10 0.09 1.0 0.12 457 19.4 22933 0.63 0.04 3445 0.27 13 3445 R2 22985 0.09 0.09 0.8 0.11 453 19.6 22969 0.68 0.04 3458 0.28 12 3458 

193R F 22940 0.14 0.12 1.6 0.12 380 23.2 22942 258.60 14.92 3446 7.63 12 3447 

R 23005 0.16 0.14 2.4 0.07 375 23.4 23007 0.45 0.03 3465 0.18 12 3466 

14.90 7.45 

194R F 22959 0.14 0.13 0.9 0.24 370 23.9 22961 1.39 0.08 3455 0.42 11 3456 

R 23032 0.10 0.09 1.1 0.18 383 23.1 23034 0.41 0.02 3470 0.22 12 3471 

Not PerformedNot Performed Not P
Veh Failure/

No. Test Repair THC NMHC CO NOx CO2 MPG THC NMHC CO NOx CO2 MPG THC NMHC 

140 20160 F 0.13 0.13 2.2 0.06 290 30.2 0.00 0.00 0.1 0.03 280 31.8 0.01 0.01 

21306 R 0.15 0.14 4.0 0.00 302 28.8 0.01 0.00 0.4 0.03 289 30.8 0.01 0.01 

141 21173 F 0.47 0.41 4.9 0.47 463 18.9 0.06 0.02 0.0 0.17 459 19.4 0.08 0.05 

21246 R 0.44 0.38 6.6 1.03 523 16.6 0.05 0.02 0.0 0.16 526 16.9 0.10 0.06 

142 21571 F 0.34 0.29 6.9 0.59 644 13.6 0.04 0.04 0.2 0.06 637 13.9 0.05 0.04 

21618 R 0.34 0.29 7.5 0.49 646 13.5 0.02 0.02 0.2 0.10 641 13.9 0.04 0.03 

143 21253 F 0.55 0.52 5.7 0.67 373 23.2 0.02 0.01 0.1 0.12 355 25.1 0.06 0.04 

21613 R 0.54 0.50 6.3 0.56 358 24.0 0.02 0.01 0.3 0.05 334 26.6 0.05 0.03 

144 21589 F 0.48 0.45 5.4 0.38 412 21.1 0.02 0.01 0.1 0.02 441 20.2 0.05 0.03 

21639 R 0.37 0.34 5.5 0.36 390 22.3 0.01 0.00 0.0 0.00 422 21.1 0.04 0.03 

145 21677 F 0.30 0.27 4.5 0.43 401 21.7 0.02 0.02 0.3 0.08 342 26.0 0.03 0.02 

21743 R 0.26 0.24 4.2 0.46 406 21.5 0.02 0.01 0.7 0.13 340 26.1 0.03 0.02 

146 21663 F 0.56 0.51 6.2 0.36 308 27.8 0.02 0.02 0.4 0.13 306 29.0 0.09 0.06 

21705 R 0.51 0.47 5.4 0.38 323 26.7 0.02 0.02 0.4 0.09 294 30.2 0.07 0.06 

147 21797 F 0.51 0.46 5.9 0.61 427 20.3 0.03 0.02 0.0 0.08 452 19.7 0.14 0.12 

21857 R 0.85 0.77 9.0 0.65 456 18.8 0.05 0.03 0.6 0.29 483 18.4 0.20 0.17 

148 21888 F 0.70 0.63 10.0 0.53 381 22.3 0.03 0.02 0.3 0.15 368 24.1 0.06 0.04 

21993 R 0.70 0.63 9.1 0.65 382 22.3 0.03 0.02 0.1 0.13 376 23.6 0.06 0.04 

149 21913 F 0.41 0.37 7.7 0.20 396 21.7 0.02 0.01 0.1 0.00 370 24.0 0.00 0.00 

22006 R 0.31 0.27 5.4 0.17 368 23.6 0.00 0.00 0.2 0.00 362 24.5 0.10 0.08 

Table A-4

 ------------------Bag 1 (g/mi)------------------ ------------------Bag 2 (g/mi)------------------ ------------------B

FTP Exhaust Results: Bags 1-3
150 21916 F 0.52 0.49 3.7 0.75 375 23.3 0.02 0.01 0.2 0.09 375 23.7 0.07 0.05 

22137 R 0.52 0.49 2.8 0.70 368 23.8 0.01 0.01 0.2 0.08 360 24.7 0.06 0.05 

151 22023 F 0.55 0.49 9.4 0.46 380 22.4 0.01 0.00 0.1 0.03 408 21.8 0.12 0.09 

22081 R 0.51 0.45 7.6 0.53 387 22.2 0.01 0.00 0.0 0.02 409 21.7 0.10 0.08 

152 22013 F 0.38 0.34 6.2 0.21 509 17.1 0.01 0.01 0.0 0.00 504 17.6 0.07 0.06 

22132 R 0.36 0.33 6.0 0.11 504 17.3 0.01 0.01 0.0 0.00 506 17.6 0.05 0.05 

153 22072 F 0.28 0.25 5.8 0.21 368 23.5 0.01 0.00 1.3 0.02 352 25.1 0.02 0.01 

22166 R 0.27 0.25 6.2 0.20 374 23.2 0.00 0.00 0.5 0.01 359 24.7 0.00 0.00 

154 22086 F 0.29 0.27 2.9 0.26 311 28.1 0.05 0.04 2.9 0.00 311 28.2 0.03 0.02 

22177 R 0.30 0.29 2.9 0.28 312 28.0 0.05 0.03 2.7 0.00 309 28.4 0.03 0.02 

155 21155 F 0.21 0.19 2.3 0.29 327 26.8 0.02 0.02 0.1 0.02 309 28.7 0.01 0.01 

22202 R 0.28 0.26 2.7 0.26 330 26.6 0.01 0.01 0.1 0.03 312 28.4 0.02 0.02 

156 22121 F 0.82 0.75 6.0 0.52 476 18.2 0.02 0.01 0.1 0.08 440 20.2 0.09 0.07 

22182 R 0.64 0.60 5.9 0.40 427 20.3 0.02 0.01 0.1 0.03 375 23.7 0.08 0.06 

182 22262 F1 0.59 0.56 3.8 0.87 366 23.8 0.04 0.03 0.2 0.11 358 24.8 0.09 0.07 

22300 R1 0.60 0.03 3.4 0.79 366 23.8 0.01 0.01 0.2 0.09 355 25.0 0.08 0.02 22518 F2 1.37 1.33 5.5 0.85 375 22.9 0.04 0.04 0.1 0.11 366 24.3 0.09 0.08 22578 R2 0.58 0.55 4.3 0.79 367 23.7 0.02 0.02 0.2 0.09 403 22.1 0.08 0.06 

183 22368 F 0.34 0.32 2.8 0.34 445 19.8 0.03 0.02 0.5 0.09 427 20.8 0.07 0.05 

22438 R 0.35 0.32 4.3 0.40 446 19.6 0.01 0.01 0.0 0.09 424 21.0 0.03 0.02 

184 22398 F 0.94 0.72 14.0 0.23 473 17.9 0.21 0.15 5.7 0.00 479 18.2 0.08 0.07 

22463 R 0.48 0.42 6.9 0.29 463 18.7 0.02 0.02 0.5 0.00 477 18.6 0.05 0.04 

185 22414 F1 0.62 0.57 6.8 0.86 508 17.1 0.02 0.01 0.2 0.06 502 17.7 0.06 0.03 

22571 F2 0.60 0.55 6.3 0.83 498 17.5 0.02 0.02 0.2 0.08 527 16.9 0.07 0.04 22471 R 0.56 0.52 7.0 0.92 495 17.5 0.02 0.01 0.2 0.06 491 18.1 0.04 0.02 
186 22612 F 0.76 0.70 9.4 0.76 552 15.6 0.03 0.02 0.1 0.17 572 15.5 0.05 0.02 

22679 R 0.72 0.66 8.4 0.89 549 15.8 0.02 0.01 0.0 0.16 567 15.7 0.06 0.04 

187 22618 F 0.51 0.48 4.7 0.94 654 13.4 0.03 0.02 0.6 0.05 560 15.9 0.03 0.03 

22712 R 0.50 0.47 4.9 0.95 682 12.9 0.03 0.02 0.4 0.07 575 15.5 0.04 0.03 

188 22609 F1 0.23 0.21 4.1 0.16 354 24.7 0.01 0.01 0.6 0.01 335 26.5 0.18 0.18 

22633 R 0.22 0.20 4.5 0.16 365 23.8 0.01 0.01 1.3 0.01 347 25.5 0.01 0.01 22694 F2 0.27 0.25 4.5 0.16 355 24.5 0.02 0.02 1.0 0.01 346 25.6 0.01 0.01 

189 22733 F 0.20 0.18 2.4 0.12 291 30.1 0.01 0.00 0.3 0.04 297 29.9 0.01 0.00 

22763 R 0.22 0.21 1.9 0.20 306 28.7 0.01 0.01 0.2 0.03 293 30.3 0.01 0.01 

190 22859 F 0.76 0.68 13.2 0.30 393 21.4 0.05 0.03 0.5 0.12 398 22.3 0.06 0.04 

22921 R 0.53 0.48 8.2 0.27 384 22.3 0.02 0.01 0.1 0.13 384 23.2 0.03 0.02 

191 22849 F 0.57 0.53 4.6 0.79 653 13.4 0.05 0.04 0.2 0.19 620 14.3 0.04 0.03 

22873 R 0.56 0.53 5.1 0.89 638 13.7 0.03 0.03 0.2 0.10 618 14.4 0.05 0.03 

192 22860 F 0.41 0.38 3.7 0.51 474 18.5 0.01 0.01 0.1 0.03 492 18.1 0.07 0.06 

22931 R1 0.39 0.36 3.1 0.38 456 19.2 0.01 0.01 0.1 0.02 484 18.4 0.06 0.05 22985 R2 0.36 0.34 3.0 0.38 467 18.8 0.01 0.01 0.0 0.01 475 18.7 0.05 0.04 

193 22940 F 0.50 0.46 6.8 0.41 383 22.5 0.04 0.02 0.1 0.02 406 21.9 0.06 0.04 

23005 R 0.64 0.58 11.1 0.27 368 22.9 0.01 0.01 0.0 0.01 405 22.0 0.06 0.05 

194 22959 F 0.61 0.58 4.2 0.27 398 21.9 0.01 0.01 0.1 0.23 390 22.8 0.01 0.00 

23032 R 0.39 0.36 4.1 0.27 391 22.3 0.00 0.00 0.3 0.14 408 21.8 0.05 0.05 
Veh

No. Fault MIL Code Drive Cycles Comments

140 Removed the gas cap On P1456 LA-4 (1)140 Reinstall OEM Cap Off None141 Purge system inoperative On P1451 No drive cycle needed True failure.141 Replaced PCM Off None142 0.040 in. leak in gas cap On P0442 LA-4 (2)

142 Reinstall OEM cap Off None143 0.040 in. leak in vent line On P0440 LA-4 (2.5)143 Removed 0.040 in. leak Off None144 Blocked purge line On P0440 LA-4 (2) Removed purge line at throttle body, plu

144 Blockage removed Off None145 Vent solenoid line to On P0450, LA-4 (2)

atmosphere blocked P1446

145 Blockage removed Off None146 0.040 in. leak in gas cap On P0442 LA-4 (2)146 Reinstall OEM cap Off None147 Purge and tank vent line On P0455 LA-4 (1) SS (1) Port disconnected from cansiter. Open 

disconnected at canister True failure.

147 Lines reconnected Off None148 0.040 in. leak in purge line On P0446 LA-4 (2) Leak in series between solenoid and fue

to fuel tank.

148 Remove leak Off None

Induced Failures, MIL and Diagnostic Trouble Code Status

Table A-2
149 Disconnect purge line at On P0440 LA-4 (2) Plugged at both ends.

throttle body

149 Reinstall purge line Off None

150 Remove gas cap Off None LA-4 (6) FTP (2) SS(1)150 Remove gas cap Off None SS (2) Continuous code P0455, No MIL.

151 0.020 in. leak in gas cap Off None LA-4 (3) FTP (1)151 Reinstall OEM cap Off None152 0.020 in. leak in gas cap Off None LA-4 (1) Steady State (2)152 Reinstall OEM cap Off None153 Block purge line On P1457 LA-4 (2.5) Line disconnected from purge valve, blo

at both ends.

153 Repair purge line Off None154 0.040 in. leak in purge line. On P1440 LA-4 (2) Leak between canister and purge valve154 Remove leak Off None

155 0.040 in. leak in gas cap Off None All readiness monitors complete, no MIL

155 Reinstall OEM cap Off None156 0.020 in.leak in gas cap On P0440 LA-4 (4) MIL on after 4th LA-4.156 Reinstall OEM cap Off None182 0.040 in.gas cap leak Off None Road LA-4 (2) EGR & evap monitors incomplete after 

all monitors complete after 2nd. No MILcodes, all TIDs and CIDs pass.

182 Reinstall OEM cap Off None Road LA-4 (2)182 0.040 in.gas cap leak Off None LA-4 (2) All monitors complete after 2nd LA-4.182 Gas cap removed On P0455 LA-4 (2) MIL on during 2nd LA-4.

182 2nd 0.040 in.gas cap leak Off None LA-4 (3) Vehicle had continuous code P0442 afte

drive trace. No cont. codes after 3rd drreadiness monitors complete, MIL off.
183 0.040 in.leak in line between On P0440 Road LA-4 (2) MIL on during 2nd road LA-4.

canister and fuel tankLeak removed from line

183 Remove leak from line Off None LA-4 (1) All monitors complete after first dyno LA

184 Gas cap removed On P0455 Road LA-4 (2) SS (3) Steady state cycles performed on dyno.184 Gas Cap Installed Off None LA-4 (1) SS (1) Steady state cycles performed on dyno.185 0.040 in. leak in line between Off None Road LA-4 (1) All monitors completed during the first r

canister and fuel tank No MIL on, no codes.

185 Fault removed Off None LA-4 (2) GM (1) EGR monitor was reset during GM trace

185 Reinstall 0.040 leak (metal) On P0442 LA-4 (2) Steel adapter put in in place of plastic a

2nd As-Received test performed.

186 Purge hose plugged On P0455 LA-4 (2) SS (4) Continuous code P0455 after first drive 

MIL on 5 minutes into the 4th steady sta

186 Remove plug from purge lin

e Off None FTP (1) SS (1) Evap only incomplete monitor after FTP

187 Loose gas cap On P0440 FTP (1) LA-4 (4) All monitors complete, no

MIL after 1st LA-4. Monitors cleared, ca1/2 in. Cold FTP trace driven. All moniexcept evap after FTP trace. No continThree more LA-4 cycles driven. MIL on into the 3rd LA-4 trace. (1 FTP + 3 LA-4 MIL on).

187 Tighten OEM cap Off None FTP (2)188 0.040 in.gas cap leak On P1456 LA-4 (2) Light on 15 minutes into the 2nd LA-4 d188 Install OEM cap Off None FTP (1) All monitors complete after 1st dyno FT188 0.040 in.gas cap leak On P1456 FTP (2)188 OEM gas cap installed Off None FTP (1) All monitors complete.189 0.020 in.gas cap leak On P0440 FTP (2)189 OEM gas cap installed Off None FTP (1) All monitors complete.
190 Purge line disconnected at On P0446 FTP (2) Vehicle procured with MIL on and fault s

canister

190 Reconnect purge line Off None FTP (1)191 Loose gas cap On P0440 FTP (2) Evap monitor incomplete, no pending co

first FTP.

191 Tighten gas cap Off None FTP (1)192 0.040 in.leak between tank On P0442 FTP (1) SS (1)

and canister.

192 Remove fault Off None FTP (1) SS (1)

193 Blocked purge system On P0440 FTP (2)193 Reconnect pur

g

e Off None FTP (3)

194 0.020 in.leak in gas cap On P0440 FTP (3)194 Reinstall OEM cap Off None FTP (2)
Vehicle 150

Gas Cap Removed

(No Mil light)

Key On Engine Off

 ̃ENGINE SPD................ 0RPM

 ̃ECT (ø).................. 111øF

 ̃VEHICLE SPD............... 0MPH

 ̃IGN. TIMING............... 0.0ø

 ̃ENGINE LOAD............... 0.0%

 ̃MAF (R)............... 1.57gm/s

 ̃TPS (%).................. 10.1%

 ̃IAT (ø)................... 75øF

 ̃FUEL STAT 1................. OL

 ̃FUEL STAT 2............. UNUSED

 ̃ST FT 1.................. 20.3%

 ̃LT FT 1................... 0.0%

 ̃O2S B1 S1............... 0.010V

 ̃FT O2S B1 S1............. 20.3%

 ̃O2S B1 S2............... 0.000V

 ̃FT O2S B1 S2............ UNUSED

 ̃MIL STATUS................. OFF

 ̃STORED DTCs.................. 0

 ̃OBD CERT................ OBD II

Continuously Monitored Systems

P0455

EVAP Control System Leak

Detected (gross leak)

Fault Code Review 

No DTCs Reported
 Freeze Frame 

Readiness States 

 ̃MISFIRE MON.............. AVAIL

 ̃FUEL SYS MON............. AVAIL

 ̃COMP MON................. AVAIL

 ̃CAT MON.................. COMPL

 ̃HTD CAT MON................ N/A

 ̃EVAP MON................. COMPL

 ̃2nd AIR MON................ N/A

 ̃A/C MON.................... N/A

 ̃O2S MON.................. COMPL

 ̃O2S HTR MON.............. COMPL

 ̃EGR MON.................. COMPL

2500 RPM 

 ̃ENGINE SPD............. 2510RPM

 ̃ECT (ø).................. 122øF

 ̃VEHICLE SPD............... 0MPH

 ̃IGN. TIMING.............. 31.0ø

 ̃ENGINE LOAD.............. 38.8%

 ̃MAF (R).............. 11.27gm/s

 ̃TPS (%).................. 12.9%

 ̃IAT (ø)................... 75øF

 ̃FUEL STAT 1................. CL

 ̃FUEL STAT 2............. UNUSED

 ̃ST FT 1.................. -1.5%

 ̃LT FT 1.................. -4.6%

 ̃O2S B1 S1............... 0.795V

 ̃FT O2S B1 S1............. -7.7%

 ̃O2S B1 S2............... 0.000V

 ̃FT O2S B1 S2............ UNUSED
 ̃MIL STATUS................. OFF

 ̃STORED DTCs.................. 0

 ̃OBD CERT................ OBD II

Engine Idle

 ̃ENGINE SPD.............. 934RPM

 ̃ECT (ø).................. 129øF

 ̃VEHICLE SPD............... 0MPH

 ̃IGN. TIMING.............. 18.5ø

 ̃ENGINE LOAD.............. 30.9%

 ̃MAF (R)............... 3.60gm/s

 ̃TPS (%).................. 10.1%

 ̃IAT (ø)................... 77øF

 ̃FUEL STAT 1................. CL

 ̃FUEL STAT 2............. UNUSED

 ̃ST FT 1.................. -7.7%

 ̃LT FT 1................... 1.6%

 ̃O2S B1 S1............... 0.865V

 ̃FT O2S B1 S1............. -6.9%

 ̃O2S B1 S2............... 0.000V

 ̃FT O2S B1 S2............ UNUSED

 ̃MIL STATUS................. OFF

 ̃STORED DTCs.................. 0

 ̃OBD CERT................ OBD II
1 hour max

Enhanced - Purge and load with 

1.5 X working capacity w/butane

ORVR - Load to 2 g 

breakthrough with butane

10 minutes

4 hours max

7 min. max

12-36 hours

6-36 hours

6-36 hours

One UDDS

Fuel Drain, Fill

Cold start exhaust test

Hot start exhaust test

Running Loss Test

UDDS, 2 NYCC, UDDS

3 Day Diurnal Loss Test

3-24 hour cycles @ 72-95-72 F

End

@ 95 F

Hot Soak Loss Test

1 hour, @ 95 F

Vehicle soak

Last 6 hrs @ 95 F

Figure A-1

9 RVP, 40% full

Canister Pre-conditioning

Start

Fuel Drain, Fill

9 RVP, 40% full

Pre-conditioning Drive

FTP Evaporative Emission Test Procedure

Vehkicle Soak

68 - 86 F
Veh Fuel Failure/

No Profile Repair Initial Bag 1 Bag 2 2 min Bag 3 Bag 4 2 min Bag 5 Bag 6 2 min

140 Target 95.0 101.4 111.6 112.1 115.3 118.0 118.4 121.2 124.8 124.5

Actual F 95.5 99.6 112.7 114.1 115.6 117.8 118.4 122.1 125.6 124.4

Actual R 94.5 99.8 111.7 112.3 115.2 118.4 117.8 122.1 125.4 125.4

141 Target 95.0 99.0 109.5 110.9 117.3 122.2 123.0 125.8 128.9 129.4

Actual F 93.8 99.0 108.6 109.8 116.4 121.5 122.7 124.4 127.3 128.1

Actual R 95.1 99.8 109.0 109.0 116.8 123.6 124.8 125.8 127.0 127.9

142 Target 95.0 97.4 103.8 104.4 108.4 112.3 112.8 115.1 119.3 119.5

Actual F 94.7 95.9 101.4 102.5 105.9 109.8 110.5 113.3 118.2 118.8

Actual R 95.1 95.9 102.0 103.1 107.6 111.3 111.9 114.8 118.2 118.6

143 Target 95.0 97.3 104.3 104.7 108.7 112.2 112.7 114.8 116.8 117.0

Actual F 94.5 99.6 105.9 105.7 108.4 111.5 112.5 115.4 117.6 117.4

Actual R 94.9 98.6 104.7 105.3 108.8 112.1 111.5 114.6 117.2 117.2

144 Target 95.0 99.5 108.7 109.1 113.1 116.3 116.7 119.7 123.6 123.8

Actual F 95.7 102.0 109.0 109.0 113.7 116.2 116.6 121.7 124.4 125.0

Actual R 94.3 99.4 110.0 110.5 114.6 116.2 116.4 120.1 124.6 125.0

145 Target 95.0 102.8 111.1 111.7 114.6 116.4 116.6 118.3 120.6 120.6

Actual F 96.3 100.8 110.5 111.9 115.0 116.4 116.2 117.4 119.4 118.8

Actual R 94.9 98.2 109.6 110.2 115.4 118.4 118.9 119.1 120.5 120.9

146 Target 95.0 100.4 110.8 111.1 113.8 117.5 117.6 120.5 122.5 122.5

Actual F 94.7 101.0 106.4 107.2 111.5 114.6 115.0 119.3 122.3 121.9

Actual R 95.7 100.8 108.6 109.2 114.5 117.4 116.8 120.1 122.5 121.5

147 Target 95.0 101.7 114.5 115.7 122.3 128.1 127.9 130.5 134.2 133.6

Actual F 94.1 102.9 114.5 115.6 121.9 127.5 127.9 131.1 134.6 135.5

Actual R 95.0 105.1 113.9 114.6 122.5 127.9 128.1 131.4 135.4 134.6

148 Target 95.0 97.5 103.8 104.7 109.3 113.7 114.6 117.6 121.4 121.6

Actual F 94.3 99.6 103.5 104.3 109.2 113.7 114.3 116.8 120.9 121.1

Actual R 95.1 99.4 103.3 104.3 109.8 113.1 113.5 115.6 120.9 121.5

149 Target 95.0 98.9 106.3 106.9 110.6 114.6 115.2 117.6 120.5 121.4

Actual F 94.1 101.2 106.2 106.4 110.9 114.3 114.6 117.0 121.3 120.9

Actual R 94.1 100.6 107.4 109.4 111.3 113.7 117.2 116.8 121.3 119.5

150 Target 95.0 99.0 106.9 107.5 115.9 120.9 121.6 123.1 125.5 125.5

Actual F 95.1 102.0 108.4 109.0 112.3 117.8 119.1 126.8 126.0 124.2

Actual R 94.9 103.1 109.0 109.0 112.7 120.1 120.7 130.1 125.4 124.0

Liquid Fuel Temperature at Start or End of Running Loss Segment, Degrees F

Running Loss Segment

Table A-5
151 Target 95.0 99.5 108.7 109.1 113.1 116.3 116.7 119.7 123.6 123.8

Actual F 93.8 99.2 108.2 108.2 112.3 116.4 116.4 119.9 123.0 124.2

Actual R 94.3 99.6 108.0 108.6 113.5 115.8 116.0 119.9 124.6 122.9

152 Target 95.0 98.0 102.4 102.9 106.4 109.9 110.4 113.0 116.0 116.6

Actual F 94.7 97.1 103.1 103.7 106.3 112.1 110.9 112.7 116.2 117.0

Actual R 94.1 97.1 102.7 103.5 106.6 110.0 110.5 112.3 115.4 116.4

153 Target 95.0 99.5 110.7 112.6 116.5 120.0 120.4 122.9 126.6 127.1

Actual F 94.3 100.0 109.8 110.7 116.6 121.5 121.9 124.6 126.0 126.4

Actual R 96.9 101.2 110.4 111.3 117.4 121.3 122.1 124.6 126.2 126.0

154 Target 95.0 100.1 108.4 108.5 113.9 117.5 117.5 120.9 124.3 124.9

Actual F 93.9 105.3 112.3 112.3 113.5 118.0 117.8 121.3 123.8 124.0

Actual R 94.1 102.8 109.0 109.0 113.7 116.8 116.6 120.7 124.2 123.8

155 Target 95.0 103.2 113.5 115.2 117.6 119.8 121.2 124.4 128.3 128.3

Actual F 94.3 102.1 112.5 115.0 118.4 120.7 121.7 125.2 128.1 128.5

Actual R 95.3 102.3 112.3 113.9 116.6 120.7 121.5 122.7 128.1 127.9

156 Target 95.0 99.3 107.0 107.9 110.8 114.9 115.6 117.9 121.5 122.0

Actual F 94.5 98.2 106.6 107.0 109.8 114.5 114.6 118.8 121.9 121.7

R 94.7 98.6 107.2 107.6 110.7 115.2 114.6 118.6 120.3 121.1

182 Target 95.0 99.0 106.9 107.5 115.9 120.9 121.6 123.1 125.5 125.5

Actual F1 94.3 100.6 107.6 107.6 114.1 119.3 121.3 123.4 125.8 127.0

Actual R2 94.5 102.0 107.4 107.6 114.6 119.7 120.7 123.6 126.0 125.6

Actual Diag 94.9 99.0 108.8 110.2 114.5 119.7 120.7 123.8 125.6 125.2

Actual F2 95.9 99.6 108.4 109.4 113.5 119.9 120.7 125.6 126.6 126.2

Actual R2

183 Target 95.0 99.2 106.3 106.8 110.1 111.3 111.0 114.4 118.0 118.5

Actual F 94.5 98.6 107.0 107.0 111.5 112.9 112.9 115.6 118.0 118.4

Actual R 95.7 98.6 107.0 107.6 112.9 114.5 114.5 117.0 119.1 117.4

184 Target 95.0 99.1 107.7 108.7 113.3 117.8 118.4 122.0 125.3 124.9

Actual F 94.9 100.2 107.4 107.8 112.7 117.4 117.0 118.2 120.9 126.6

Actual R 93.8 101.8 107.8 108.2 113.3 116.0 117.4 121.3 126.0 126.0

185 Target 95.0 98.1 104.8 105.2 109.2 113.8 114.0 117.5 121.5 121.6

Actual F1 93.9 98.0 104.3 104.9 108.4 113.9 113.9 116.6 121.7 122.5

Actual F2 94.7 97.9 105.7 104.7 108.4 113.3 114.5 117.4 121.9 121.9

Actual R 94.3 97.7 105.1 104.9 108.6 113.7 114.5 116.8 121.5 122.5

186 Target 95.0 98.9 107.2 107.7 111.8 115.8 116.4 119.3 122.5 122.9

Actual F 96.5 100.6 106.8 107.2 111.3 114.6 115.0 117.8 120.5 121.5

Actual R 95.3 99.0 106.6 107.4 111.1 115.2 115.6 118.8 121.7 123.0

187 Target 95.0 97.4 105.3 105.6 110.3 113.1 113.3 116.7 119.9 120.0

Actual F 95.5 99.0 104.5 106.1 110.9 113.0 114.8 117.2 119.7 120.5

Actual R 95.1 98.4 103.1 104.1 109.8 113.7 114.3 116.6 119.7 120.9
188 Target 95.0 99.5 110.7 112.6 116.5 120.0 120.4 122.9 126.6 127.1

Actual F 96.1 100.0 111.1 111.9 116.4 120.9 120.1 122.7 127.1 126.6

Actual R 95.9 100.4 110.7 110.7 116.2 119.7 119.7 123.4 127.7 127.7

Actual F 95.3 99.4 109.8 111.3 117.4 120.1 119.9 121.3 126.0 127.0

Actual R 95.7 99.4 110.2 111.9 118.0 120.5 120.7 121.7 126.4 126.8

189 Target 95.0 98.5 104.9 105.0 108.3 111.4 111.5 114.5 118.2 118.2

Actual F 95.9 98.6 105.1 105.7 109.2 111.7 117.7 113.7 118.9 118.9

Actual R 95.9 99.4 105.7 105.7 109.0 111.9 111.1 115.0 117.6 117.6

190 Target 95.0 97.5 103.8 104.7 109.3 113.7 114.6 117.6 121.4 121.6

Actual F 94.1 96.7 102.0 103.9 108.4 113.1 113.7 116.0 119.9 120.3

Actual R 94.5 97.5 104.1 104.9 109.6 113.7 113.9 116.8 120.7 120.9

191 Target 95.0 100.3 109.4 110.4 114.6 118.4 119.4 120.6 123.5 123.5

Actual F 93.9 97.5 107.4 107.8 113.1 116.8 118.0 120.7 122.9 122.5

Actual R 93.6 98.8 108.8 108.8 114.1 118.0 118.8 122.1 125.8 125.6

192 Target 95.0 97.6 104.2 104.8 108.8 112.7 112.4 115.2 119.0 119.2

Actual F 93.6 96.1 104.3 105.9 110.4 113.1 113.3 115.2 118.8 119.9

Actual R1 94.1 99.0 105.1 105.7 109.4 112.1 112.1 114.6 119.9 120.3

Actual R2 94.3 97.3 105.7 106.4 110.7 113.1 114.1 115.8 118.9 119.1

193 Target 95.0 99.9 110.7 111.0 114.8 118.5 119.2 123.1 126.7 126.7

Actual F 94.1 99.2 110.2 111.7 116.4 120.1 120.9 124.0 125.8 126.2

Actual R 94.1 99.0 109.6 110.2 115.2 119.9 120.7 122.1 126.2 127.0

194 Target 95.0 99.6 109.1 109.3 113.1 117.9 118.4 121.5 124.8 124.8

Actual F

Actual R 95.1 98.8 109.0 110.0 115.6 117.6 118.2 120.7 127.3 127.7