Please Help! 14 DTCs. Air Bag, EVAP, EBCM, dash lights, dimmer pro

Lemon Truck · October 8, 2015

Hello,

I recently bought a 2000 GMC Sierra 2500 extended cab SLT 2wd with the 5.3L. I was very excited about this truck initially as I got it at a great price, but I am starting to become overwhelmed with all of its problems I recently discovered.

The previous owner purchased this truck at an auction, and put a lot of new parts on it mechanically and cosmetically. There are a lot of mis-matched parts on this truck and I can tell it is somewhat of a "Frankenstein." One thing I noticed is that there are 4x4 buttons on the dash, even though this is a 2wd truck (no T-case). So obviously someone put a new dash on from a 4wd donor. Also, the plastic around the ignition cylinder looks like its been monkeyed with, so someone was probably fooling around near the steering column.

When I test drove the truck, the only light on was "Service Engine Soon." However, when I brought my truck to get an OBDII scan at the parts store it returned 14 codes (some duplicates) which are as follows:

B0017 - Passenger frontal deployment loop open

B0024 - Driver deployment loop short to ground

B0036 - Discriminating sensor open or short to voltage

B0051 - Deployment commanded

C0265 - EBCM relay circuit

P0430 - Catalyst system - Low efficiency (Bank 2)

P0440 - EVAP system

P0449 - Evaporative canister vent solenoid control circuit

But, NO lights are ever on the dash except the SES. Shouldn't the airbag or SRS light be on as well? On startup the only lights that come are the SES, nothing else. All the gauges work, although they bounce oddly when I shut off the truck. The voltage needle also twitches very slightly when I use the turn signal. Also, when I turn on the headlamps, the only thing lit up is the cluster. The radio, climate controls, and everything else is dark. And, when I cleared the codes with the ODBII scanner, the radio went off and reset itself to 1:00?!

I have literally spent hours on end searching in vain for a definitive answer to this host of problems with only little success. I am guessing that the "B" codes mean that I need a new SDM? Perhaps this truck was in a wreck?

P0430 might be because of a small exhaust leak this truck has, or possibly the cat is bad. P0440 and P0449 might mean I need a new EVAP solenoid or can?

Please help me, it would be greatly appreciated. This truck means a lot to my little family as it is how we are getting across the country for my new job in Tallahassee. Any insights would be very welcome. Thank you all.

Lemon Truck · October 9, 2015

I took apart my dash today and found two yellow wires under the dash that looked rubbed through to bare wire then had been electrical taped. I also found a brownish small wire that was completely severed. I reconnected the brown wire and retaped the yellow wires. I took out the cluster but couldn't get at the board to see if the little bulbs were broken off. I checked every single fuse in the whole truck inside and under the hood and all the fuses are good. However, someone removed the giant ABS fuse and the giant one for "air" or whatever is missing completely. I also put on a gas cap from the junkyard that appeared to be newer and in better condition.

I also had my truck rescanned (as last time I erased the codes) and now I only have two codes p0449 and b0017. Were the 14 codes just old ones that were stored? Also, how can I get the ABS, cruise, seatbelt, brake and other lights to work on the cluster? Do I have to buy a new one? If I buy a new cluster does that mean the total truck mileage changes? I bet this truck had 300,000 miles and they swapped out the cluster for one that had only 144,000. What is up with the b0017? Does p0449 mean that I need a new EVAP solenoid? And I still have no lights on the radio, climate or other stuff at night, only the cluster and the door buttons.

I'm spending hours tearing apart my truck and researching old threads and goolge but I need help desperately.

Thanks guys.

Lemon Truck · October 10, 2015

Could anyone with a carfax or autocheck subscription possibly run my VIN? I would really appreciate it.

Lemon Truck · October 10, 2015

Took apart my dash today and it looks like the air bag is still in the passenger side. Don't know what it's supposed to look like but its all folded up in there. Also found the connector unplugged for the passenger airbag. It is obviously unplugged because the two connectors are completely different. Someone must have replace the entire dash and it must be from a different year or model. Also I looked at the cluster and someone broke off the little bulbs for the brake ABS and air bag. It looks like they unsoldered it so I think I can solder them back in if I can get the computerboard off without breaking it. Does anybody have any idea what model and/or year my dash might be from? Is it possible to hardwire the two connectors together even though one has two wires and the other has 4? How do I solder new LED bulbs on board? Thank you very much.

PIC 1: Top connector from wrong dash (goes to pass airbag), bottom connector from truck harness

PIC 2: Pic of passenger airbag on/off connector

PIC 3: Diagram of pass airbag connectors and wire colors

txab · October 10, 2015

The bulbs are gone because they were on all the time. The PO removed them. I sure hope you got a great deal on this truck

Lemon Truck · October 11, 2015

I had it inspected by the GMC dealership and they said everything was solid. Of course they didn't scan for codes. Except for the dashboard/airbag issue everything is fine. I think someone replaced the original dash with one from an 04' Sierra. This would explain why it still fits correctly but some of the connectors are different. Is there anyway to hardwire the two different connectors for the passenger airbag? I have the pinouts but I'm not skilled enough to decide if I can splice them together.

Motor City Rick · September 3, 2017

Clear "ALL" the codes. Warm up the truck for about 10 to 15 minutes, see what codes return quickly on the first round. List these codes here. This is going to be one major cluster fl*k!!!

You made one important statement, "I'm not skilled enough to decide if I can splice them together". In dealing with any air bag, ...if you are not "skilled" with the air bag system, ...don't screw with "any" aspect of it. One wiring / repair screw up can deploy the bags at the worst time causing very severe injury / death. Have a "professional" deal with that type of repair.