ECU Repair, unidentified EPROM/Serial Flash. - Page 1
Forum section: electronics / repair

author: TheBay
author_rank: Unknown
timestamp: August 31, 2015, 06:56:52 pm
content: Trying to repair the ECU on one of my cars, the ECU is water damaged and I can't repair it (Multi layer tracks gone and main connections)I can buy a replacement ECU, but I need to hex edit the next ECU to contain the information of some modules, mainly the Immobiliser,The keys are stored in the Immobiliser so all is fine there.I am trying to read the serial EPROM however it a Fairchild device, 8 pin SOIC package with the following markings: B02AF which brings up bugger all on google apart from some sales listings in China,I have tried most 93C devices but it's reading it as all 0000's.The programmer I am using is a MiniPRO TL866A (Genuine Version)Can someone ID this flash chip, or have an idea how I can find out what it is or what other chip types I can try.

author: andybarrett1
author_rank: Regular Contributor
timestamp: August 31, 2015, 09:02:28 pm
content: Have you tried :-http://willem.engen.nl/projects/DC5xx/FM24C03U.pdfI do know a lot of car ECU' s and boat ECU's use this Fairchild device ?24c02 maybe ?..

author: TheBay
author_rank: Unknown
timestamp: August 31, 2015, 09:20:25 pm
content: Thanks for your reply, I tried the one you linked to and also the 24c02 but get all FFFF's, so it's not that oneI have a feeling the eprom is buggered.Quote from: andybarrett1 on August 31, 2015, 09:02:28 pm

author: andybarrett1
author_rank: Regular Contributor
timestamp: August 31, 2015, 09:30:46 pm
content: Bugger.... Worth a go sorry

author: TheSteve
author_rank: Unknown
timestamp: September 01, 2015, 02:23:41 am
content: Who makes the ECU and what car is it from?

author: andybarrett1
author_rank: Regular Contributor
timestamp: September 01, 2015, 08:34:29 am
content: Can you verify clock lines, supply and addressing connections physically to the chip on the board.Might give you a hint of what device is or isn't ?BRAndy

author: TheBay
author_rank: Unknown
timestamp: September 01, 2015, 09:53:53 am
content: It's a Hitachi ECU from a Suzuki Grand Vitara V6Quote from: TheSteve on September 01, 2015, 02:23:41 amI don't have the board any more, I drove to a Suzuki specialist who said he had the same ECU there and would exchange mine, turned out the one he has is 1 model number different so wouldn't work 100% Mine is OBD his wasn't, so I borrowed his ECU to get my car going to move it and going to post that ECU back, I gave him mine for spares for loaning me the ECU.Quote from: andybarrett1 on September 01, 2015, 08:34:29 am

author: mos6502
author_rank: Frequent Contributor
timestamp: September 01, 2015, 11:16:21 am
content: Get one of those $10 Saleae logic analyzer clones and just hook it up to all the pins. That'll tell you right away which pin is doing what and what kind of protocol it's using. It'll also decode I2C or SPI for you so you can see exactly what's happening.

author: TheBay
author_rank: Unknown
timestamp: September 01, 2015, 01:34:27 pm
content: Sounds a useful device! Might grab one.Quote from: mos6502 on September 01, 2015, 11:16:21 am

author: TheSteve
author_rank: Unknown
timestamp: September 01, 2015, 04:56:14 pm
content: Something to consider for the future is that a lot of automotive eeprom's have reversed pinouts.