OK so I have had this 2000 Silverado 4.8L in my driveway for a couple days, been trying to figured out what the heck is wrong with it.
We put a new PCM in it and it still wont run.
It cranks, has spark, but I am assuming it is not getting fuel.
I sprayed carb cleaner into the throttle body and it starts up and runs for a couple seconds, then dies.
I noticed the oil pressure sensor was showing -15.4 psi...that correct... NEGATIVE 15.4
So I was wondering, did GM oncorporate a safetly feature into these that shuts off the fuel pump if the oil pressure is too low or the oil pressure sensor goes out?
I purged the fuel pressure relief valve and fuel comes out but it doesnt "spray", it kindof just dumps a little out then nothing after that..no pressure.
So I am assuming it is not on or is going out.
Also, I have been having trouble blowing the ECM B fuse on the truck... it will crank a bit then blow the fuse. I have went through a few boxes of fuses already. Here are the codes I am getting:
[PCM] P0102 - Mass Air Flow (MAF) Sensor Circuit Low Frequency (Immature)
[Brake] C0226 - LF Wheel Speed Signal Missing (History)
[Brake] C0222 - RF Wheel Speed Signal Missing (History)
[Unknown] B3148 - (History) (Immature)
[Unknown] U1255 - Class 2 Communication Malfunction (History) (Immature)
[Unknown] B2648 - (History) (Current) (Immature)
[Unknown] U1016 - Loss of Class 2 Communication with VCM (History) (Immature)
[Restraints] U1000 - Class 2 Communication Malfunction (History) (Immature)
[Restraints] U1016 - Loss of Class 2 Communication with VCM (History) (Immature)
[Restraints] U1041 - Loss of EBCM Communication (History) (Immature)
[Restraints] U1096 - Loss of Communications with IPC (History) (Immature)
[Restraints] U1064 - Loss of Communications with DIM (History) (Immature)
Continuous Tests
Misfire: Complete
Fuel System: Complete
Comprehensive Component: Complete
Once Per Trip Tests
Catalyst: Incomplete
Heated Catalyst: n/a
Evaporative System: Incomplete
Secondary Air System: n/a
A/C System Refrigerant: n/a
Oxygen Sensor: Incomplete
Oxygen Sensor Heater: Incomplete
EGR System: Incomplete
The MAF code is OK..I unplugged it to prevent it from dumping even more fuel earlier....I was experimenting, wasnt sure if the plugs were fouled or not so I pulled the injector fuse and cranked it for a bit then unplugged the MAF and tried to crank. Finally I figured maybe check the fuel pressure relief valve and found that it wasnt getting much fuel at all. Thats when I sprayed the carb cleaner in the throttle body. Then it cranked and ran for a couple seconds.
Anyways...whats the deal with all these codes? I was driving when I got it but running very poorly. It was stumbling at idle and part throttle, but WOT was OK about 3000 rpms.
Another thing is the new PCM is from Autozone. I have had nothing but good luck with their PCMs in the past when one went south. Is this PCM bad? Or what could the reason be behind all those DTCs?
This is my sisters boyfriends truck and he just thought his alternator was going out and we ended up having all kinds of problems with it.
Any help at all would be greatly appreciated
thanks!