I am troubleshooting an ABS issue (P1669) that was originally accompanied by a P0502 DTC. Looking at live data, the VSS is showing 0MPH at all times. So I replaced the VSS even tho it ohmed correctly (only $20.00). Occasionally the ABS light goes off and the VSS starts reporting the vehicle speed correctly once again, although most of the time the ABS light is on and the VSS shows 0MPH on the scan tool.. I'm thinking that I need to check the wiring harness between the ABS module and the VSS. I'm guessing that the VSS signal is going through the ABS module before it gets to my scan tool but that's just a guess. Does anyone have a wiring diagram for the ABS system (2002 Saturn L300) ?
A pin-out for the connector at the ABS module would be a great help !
Also looking for wiring between the ABS module and the PCM...

 

I don't have a wiring diagram, but I have to agree with you line of reasoning. If you can get to the connectors easily enough, I'd try unplugging them (battery ground disconnected) and using some electrical contact cleaner on them. Then I'd plug them back in and unplug them several times to help sweep the contacts clean.

 

I figured there's the possibility that unplugging the connectors a few times could solve the problem although I've never been so lucky...
Your Mark Twain is amusing !!!

 

Thanks, my luck never runs that way either. And the Mark Twain thing has become very popular in the media in the past 20 years or more! LOL

 

For any one else experiencing this or similar... OBD2 code P1669 accompanied by P0500 (VSS Sensor).
Live data showed 0MPH from the VSS. What was confusing is that the speedometer still functioned perfectly.
This is the only thing I could find on the internet:
_____________________________________________
Make:SaturnCode:P1669
Definition:Antilock Brake System Unit Expected
Description:Engine started, engine speed over 600 rpm, ECM/PCM has ABS programmed as an option, and the PCM did not detect a Torque Reduction signal from the EBTCM over Circuit 463 for 2 seconds.
The EBTCM sends torque reduction request information to the PCM over Ci
Cause:

• Record any related trouble codes in memory
• Replace the PCM and program the new PCM
• Perform the Security System (Passlock) Relearn Procedure

_____________________________________________
So this was essentially telling me to replace the PCM
I had a hard time blaming the PCM when it appeared to be doing its job of reporting a failed response from the ABS module.
I got a used ABS unit on EBay for $25.00 and replaced just the module portion of the ABS and the problem is solved.
'Not an easy task to access the module without removing the entire ABS unit, but it can be done with some scrapes and cussing...
Apparently it is impossible to bleed the brake system on this vehicle without a scan tool that can run the ABS through a series of steps to purge all of the air from the ABS.
If you can do it without removing any hydraulic lines, it is well worth the effort.

 

Nice job, sir

 

Thanks for getting back to us and letting us all know that you got the problem solved. I LOT of people never return to let us know. We appreciate it and hope you stick around. Andy is our L series guru and he will be the one to give you the most help.