philc11

I need a lt1 tech to give some advise please. I have a 94 formula that has a vortech sc, cnc heads, 030 sc pistons, ts rings, and lots of ecm work by the previous owner and breathless performance. I bought the car with the motor in pieces and have just started to get the car driveable again. Once I have rectified the basic wiring problems, I have a few dtc's I'd like to get some insight on since they might be related. I do have a snap-on scanner and vantage scope but no gm service manual. My hard codes are as follows: 11 MIL, 18 crank, 26 quad mod 1, 27 egr elec (manifold egr input port plugged), 32 egr, 83 tc quad and 84 3-2 ds (I have a 6 speed though????). Finally, I have an airbag code 26 driver initiator that is driving me crazy and sets the ses light on. Anybody out there that can help?

Phil

Injuneer

You have to start with a decent list of DTC codes - you are using some sort of a generic list, or possibly one for a 93, which is the only year that uses the "quad driver" codes. There is a resonably reliable list at the end of my ScanMaster writeup:


SCANMASTER WRITEUP

11 = SES lamp circuit (wiring problem or bulb burned out or not connected)

18 = Injector circuits (PCM is not seeing the expected current flow in one or all of the eight injector circuits.

26 = EEC canister purge solenoid circuit (no load detected on solenoid circuit)

27 = EGR solenoid circuit (no load detected on solenoid circuit)

32 = EGR recirculation

83 = M6 reverse lockout solenoid circuit (no load detected on solenoid circuit)

84 = M6 skip shift solenoid circuit (no load detected on solenoid circuit)

Can't help you on the airbag code. Did you get that by looking at the DERM?

Just offhand, I'd say you have a power supply problem... look for a blown fuse or fuses. The injectors and solenoid need +12V supplied from the battery, via fuses. The PCM connects the load to ground to activate the circuit. Or maybe you have one of the wiring harnesses crushed.

32 is a bit of a mystery.... that means the PCM is not detecting the required blip in MAP that it expects when the EGR valve opens.... but that test is usually ineffective on the OBD-I (93-95) cars. Maybe when you fix the EGR solenoid it will clear.

philc11

Thanks for the help - you were right on. My snap-on MT2500 scanner registered the proper DTC numbers with the wrong descriptions. Perhaps someone previously used a funky BIN in LT1edit? Anyway, it was a power supply issue (previously modified/cut wires and hidden inside the wire harness bundle - $#ckin pain). Thanks again. Any idea where I can get some help with the remaining SIR DTC 26?