Trans AM 22502

I have a 93' T/A A4 that is being heavily modded as we speak. Because of the mods, the PCM had to be upgraded/replaced. After all of the parts were installed and the PCM came in, my engine builder is saying that he's getting a message saying "Bad Quad Driver". Apparently there are several of these drivers and it names #1 in particular. The list of mods that were done are as follows:

1995 LT1 longblock (new, crate engine)
LE2 Heads w/ custom billet cam
LE Intake port
Racetronix 42 lb. FI's
Racetronix (Walbro) 255lph FP
Taylor 8.5mm wires
NGK TR55 plugs
Comp Cams 1.6rr's
Comp Cams rocker studs
1-pc chromoly pushrods
LPP 3" LT headers and ORY
Magnaflow cat-back exhaust
Meziere EWP (wiring harness made by engine builder for this)
Yank SS 3600 stall converter
B&M 24,000 BTU tranny cooler
Performabuilt Stage 2 tranny
3.73 gears (additional gear installed to ensure sync with speedo)
Cloyes double roller TC
Melling HV Oil Pump

He fired the car up on Thursday to break the engine in and run heat cycles on it and said it ran fine. The next day when he did the same thing, he received this message and said the car began to "run rough".



FYI: NO catalytic converter, AIR & EGR delete, TB bypass. purchased all parts necessary to ensure that 95 opti will connect and work with 93 wiring harness. He said that the O2 sensor and Engine Coolant Temperature sensor are not on the car right now.

EDIT: He says that the performance is sporadic, sometimes it runs good, sometimes it doesn't.

Injuneer

The ECM is going to have a hard time running the engine correctly without the O2 sensors (your car has two) and the coolant temp sensor. The coolant temp sensor is critical to variables like idle speed and A/F ratio. What does he mean by "not in the car right now"? Pointless to even try and tune it without everything connected.

The 93 ECM (PCM was not used until 94, when is became the "powertrain" control module) uses the quad driver modules to handle high amp loads like solenoids. QDM #1 controls the AIR pump relay circuit, the EGR solenoid and the EVAP solenoid. If you have deleted the AIR system, you will not get a code unless the fuse in the circuit is blown or missing. Check the fuse. If you deleted EGR, including the EGR vacuum solenoid, you will get the DTC 26 QDM#1 code for the missing solenoid in the circuit. Put a 2Kohm resistor across the EGR solenoid harness connector pins.

DTC 26 will not cause it to run badly. But it will cause the coolant fans to run all the time. But missing O2 sensors and CLT sensor will cause serious problems. You should have codes for those as well. Without the coolant temp sensor, the ECM may be using the cold start A/F enrichment, which could overfuel the engine, and wash down the cylinder walls, causing serious problems with the rings.

Trans AM 22502

Thanks as usual Injuneer, I need to get my ears checked because I misinformed you yesterday. He was getting an Error Code stating that the ECT was malfunctioning. However it was installed and the scanner and the gauge were both reading the same temperature.

My guess is that the radiator had all types of gunk and was even rusted inside when he flushed it, so maybe this lead to a false reading due to coolant flow restriction?? In any event I replaced it with an OEM radiator because it was running hot, most likely due to restrictions in the radiator. There is after all a new WP, 160* T-stat, and the ECM tuned to turn the fans on at 160* as well.

He hooked up the scanner to get the code (so that I could give to you) when I called him today but the code was no longer there. With regards to the O2 sensors, both were installed on the vehicle but ONE of them was bad. He is going to replace both O2 sensors today and try and run it again.
As far as the AIR and EGR deletes, the ECM was not throwing any codes for either, the only code/issue was with the bad O2 sensor and a code for the ECT.

The car has been sitting for quite some time and when he removed the ECM to ship it to Ion at madtuner he noticed corrosion on the wiring harness and the gasket around the ECM was really wet, however the ECM itself was dry and in good condition according to Ion. Additionally, although I'm worried about that corrosion in the harness (which he cleaned, removed as best he could) he says it doesn't APPEAR to have affected the performance of any of the electrical components of the vehicle.