OBD PCM flash

Tiny
ANAGOECHO
  • MEMBER
  • 1995 CHEVROLET CHEYENNE
  • 5.7L
  • V8
  • 2WD
  • AUTOMATIC
  • 297,500 MILES
How can you flash the OBD without a reader? I understand that a jumper from A to H should generate a flash sequence to ID the code related to the ABS. I get nothing: key on, off, jumper in before tuning key to on, jumper install after key is on, all the above with the engine running or all the above with a start of the engine. Do you need to jump A to B to enter diagnostic mode and if so does that jumper need to remain in place while conecting to the H pin to read the ABS codes?
Wednesday, January 10th, 2018 AT 12:15 PM

1 Reply

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,489 POSTS
Hello,

I would check the ground wire for a break or corrosion.

Here is a guide to help you see how to retrieve the codes:

https://www.2carpros.com/articles/buick-cadillac-chevy-gmc-oldsmobile-pontiac-gm-1983-1995-obd1-code-definitions-and-retrieval-method

Here is the ALDL connector wiring diagrams so you can see how the connector works.

Also, check all fuses.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Check out the diagrams (below).

Please run this test and get back to us.

Cheers, Ken
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Thursday, January 11th, 2018 AT 1:52 PM

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