lol take a stab at this...

NYSpeed Automotive
1

The run down I bought a 1994 SL 5spd for a winter car…

It was stalling and running bad…Pulled the codes it was the EGR.

The quick fix to replaceing it was just unplugging the EGR…car ran fine for 2 months check engine light was on and off no probblems for me car ran great.

Fast forward 2 months

Now with the car fully warmed up it would run rough…once the car settled at idle at a stop light 800rpmsor so…it it would start to sputter and rpms would drop a little then a little more then would stall…You can two foot the car and keep it running just fine.

Car idles fine with the check engine light on
Car idles fine before it is warmed up

I replaced the ECTS(engine coolant temp sensor) twice just to make sure it wasnt a bad sensor…that fixed the rough idle part…but the stalling issue is still there.

Cleaned out the throttle body and did a top end cleaner.

I reset the PCM still have the same issue.

Its throwing codes

26 & 27 QDM Errors
32 EGR

I know those two are related because I unplugged the EGR so they can be disregarded

Its also throwing

41 These are ignition controler codes
42

48 Ref pulse

52 Low batt voltage

Anyways I messed with it a bit today…

I found a decent size hole in the elbow connector(at the throttle body) in the tube that runs from the MAP that hooks to the throttle body…

Fixed it took it for a spin…car runs much better…

Still stalls out at a stop once warm…BUT as soon as it stalls and you restart the check engine light comes on and it runs fine…

I will use the scan tool on it tomorrow at work hopefully I will get a more useful code.

Any input? Im guessing IAC or O2 at this point…

2

the QDM codes stand for “Quad Driver Module”, if you are getting these codes odds are they are the causing all the other codes. Quad drivers are a series of ground side drivers that complete circuits for components and drive these components. If the QDM has failed you will have 4 various components that will not work properly. A quick look at the schematic will show which components are on that specific QDM. IF this took a dump you will need a PCM. Good luck, that or you have a short somewhere which is pulling all the circuits down but that is rare. Try replacing the PCM those should be plentiful in M+M u pull it.

3

94 sl? benz? sl 3kgt?

4

I think its a Saturn

5

or saturn lol… my bad

6

yup its a saturn

7

There was a short in the EGR wiring fixed that…still had the idle issue…

But with all data & a scan tool this probblem was a lot easier to fix…got it narrowed down to the PCM, Ignition module or Wiring between the two…used the flowchart in all data…and a volt meter yay…

In the end it was the ignition module.

So I ended up fixing what started out at 10 DTC codes…