OBD II Not Connecting

[THEFERMANATOR]

Unplug the ABS and see if you can read the ECM then.

 

[Big T]

Unplug the ABS and see if you can read the ECM then.

Alright, unplugged the two plugs on the front driver's side corner of the ABS pump and......................................my code reader reads the ECM. Looks like I owe THEFERMANATOR and Paveltolz a ribeye dinner.

So is my issue the ABS pump? Where do I go from here?

 

[THEFERMANATOR]

Sounds like your ABS module is bad. It is replaceable seperately from the ABS pump unit. When you take the screws out of the plastic cover on the ABS unit, it lifts off of the pump unit. I know this was a common problem for GM on the 99-02 trucks because they mounted the ABS unit under the cab, and water would get splashed up into them under the truck. It looks like from the catalog there is 4 different ones that could fit it. If you go to a boneyard and find one from a 99 SUBURBAN, TAHOE, YUKON of the same body style, it should work.

 

[Big T]

Here's a video of the code reader connecting to the OBD II...

Sounds like your ABS module is bad. It is replaceable seperately from the ABS pump unit. When you take the screws out of the plastic cover on the ABS unit, it lifts off of the pump unit. I know this was a common problem for GM on the 99-02 trucks because they mounted the ABS unit under the cab, and water would get splashed up into them under the truck. It looks like from the catalog there is 4 different ones that could fit it. If you go to a boneyard and find one from a 99 SUBURBAN, TAHOE, YUKON of the same body style, it should work.

I have the entire ABS pump from my son's '95. If the module is the black plastic part that lifts off the pump unit, will the one from the '95 work?

 

[Big T]

Here are photos of the Code Reader linking up to the OBD II....

 

[Big T]

Alright, went ahead and installed the ABS Module from the '95 and the Code Reader communicates with the OBD II.

Lucky me as the ABS pump was the last thing I harvested from the '95 wreck.

 

[THEFERMANATOR]

Your problem is the 95's ABS module is OBD1, not OBD2, so you will not be able to read codes from it if there is a problem with it. 95 was a 1 year only, then 96-99 was OBD2. Same basic module, just used OBD2 instead of OBD1. Also being OBD2, I don't know if it will correctly illimunate the brake and ABS lights as the wiring may have changed with the change to obd2.

 

[Big T]

Your problem is the 95's ABS module is OBD1, not OBD2, so you will not be able to read codes from it if there is a problem with it. 95 was a 1 year only, then 96-99 was OBD2. Same basic module, just used OBD2 instead of OBD1. Also being OBD2, I don't know if it will correctly illimunate the brake and ABS lights as the wiring may have changed with the change to obd2.

Got it. I will hunt one down at a bone yard. In the interim, I should be able to pass smog because reading the OBD II was the issue holding me up. It sounds like I've also found the solution to my historic/chronic ABS problem.

 

[Big T]

Sounds like your ABS module is bad. It is replaceable seperately from the ABS pump unit. When you take the screws out of the plastic cover on the ABS unit, it lifts off of the pump unit. I know this was a common problem for GM on the 99-02 trucks because they mounted the ABS unit under the cab, and water would get splashed up into them under the truck. It looks like from the catalog there is 4 different ones that could fit it. If you go to a boneyard and find one from a 99 SUBURBAN, TAHOE, YUKON of the same body style, it should work.

So, does it need to be from a '99, or can it be from '96 to 2000 Suburban, Tahoe or Yukon?

 

[THEFERMANATOR]

99 would be best, but a 96-00 of the same body style should work so long as it's a US model. There was a Canadian version as well as a European version(shouldn't see many of them here in the states).

 

[Big T]

I picked up an ABS module from a '99 K1500 Suburban gasser in a Pick a Part boneyard. Installed it and it did not solve my ABS problem, but my Code Reader still communicates with the OBD II.

 

[Paveltolz]

I picked up an ABS module from a '99 K1500 Suburban gasser in a Pick a Part boneyard. Installed it and it did not solve my ABS problem, but my Code Reader still communicates with the OBD II.

Was code reader communicating while the 'new' ABS module all connected up or disconnected/unplugged like the old ABS Module?

 

[Big T]

Was code reader communicating while the 'new' ABS module all connected up or disconnected/unplugged like the old ABS Module?

Everything connected up with the "new" ABS module and the code reader communicates with OBD II.

Pretty sure it will pass as is. No codes and running great. The only subjective part is the acceleration snap test where I do get a puff of black smoke, but it's not bad with the GM Turbo.

Still want that ECM from Browning for insurance in case I don't pass the snap test.

I tried to pull ABS codes, but same as before with this Code Reader. It has ABS capability, but not for GM Trucks in 1999. Gets to the level where you select the 4th or 5th Cahracter from the VIN# and "K" is not an option.

 

[THEFERMANATOR]

Everything connected up with the "new" ABS module and the code reader communicates with OBD II.

Pretty sure it will pass as is. No codes and running great. The only subjective part is the acceleration snap test where I do get a puff of black smoke, but it's not bad with the GM Turbo.

Still want that ECM from Browning for insurance in case I don't pass the snap test.

I tried to pull ABS codes, but same as before with this Code Reader. It has ABS capability, but not for GM Trucks in 1999. Gets to the level where you select the 4th or 5th Cahracter from the VIN# and "K" is not an option.

I think it's just something with GM ABS. I borrowed a TECH 1 to scan my ABS when I was having a problem, and it wouldn't connect to mine. Ended up doing it the paper clip way, and read flashes of the light to get the codes out.

 

[Big T]

I think it's just something with GM ABS. I borrowed a TECH 1 to scan my ABS when I was having a problem, and it wouldn't connect to mine. Ended up doing it the paper clip way, and read flashes of the light to get the codes out.

Which pins do I use for the paper clip? What's the flash sequence?

 

[ak diesel driver]

paperclip only works on obd1

 

[THEFERMANATOR]

Which pins do I use for the paper clip? What's the flash sequence?

paperclip only works on obd1

What he said. One of the reasons I'm glad mine is a 95 is the ABS and airbag is still OBD1, so it was all stand-alone from the factory. OBD2(96+) is all mandated to use a universal conenction, and universal data protocols, so no more self diagnostics without a scanner of some sort.

 

[Paveltolz]

Check, er ECM is in the mail (UPS actually). I sent it to the cabin at the lake to give you an excuse to go play in the snow....joke. It will at the house Friday.

 

[Big T]

Check, er ECM is in the mail (UPS actually). I sent it to the cabin at the lake to give you an excuse to go play in the snow....joke. It will at the house Friday.

Thanks Paul.

My approach will be to first try and get it passed with the existing ECM which is now communicating. I estimate a 90% probability of success here. Where they would fail it is on the acceleration snap test, but it is running pretty clean with the GM Turbo on there. If that fails, I will see if they're pulling VIN # during the test. If not, swap in the stock ECM and retest it. If they are pulling VIN #, then I'll need to have the new ECM flashed with the VIN # and stock tune.

Once I am passed, I will have a Smog Test Crash Kit with instructions or notes, for my biennial smog check. With that done, I will consider a KOJO tune for the ATT.

 

[Big T]

Short story: PASSED

With the ECM communicating to my code reader, I took the truck in for Smog Test during my lunch. Chose a location in Santa Ana with the garage facing into the wind. They didn't even do a snap test. They spent an inordinate time looking for an EGR that my engine never had. They had a manual which said all 1999 and 1998 models with turbo had an EGR. Anyway, they passed it.

My back-up ECM arrives tomorrow.