02 Deville ABS/ traction dash lights

[SeaneOday]

Can anybody give me a little advice here.

I posted before with this issue- here's where I'm at;

The only current codes I have are these

ABS c1214- system relay contact

ABS c1248- EBCM turned warning light on

I tried cleaning all the wire connections and resetting. Code went away for a week and returned, it's here to stay now. I have no issues with my brakes, they seem to work fine but I haven't needed to activate ABS or the traction control.

I believe it to be a bum ECBM. I've brought it to my mechanic (great guy but not a Cadillac tech) he believes it can only be replaced by the dealer because it must be reprogrammed to fit my car BUT he wasn't sure if that included my 2002 model.

Any advice? Any suggestions where I could look, what I should try or personal experience with this issue?

[Logan]

C1214 Diagnostic tree. The last line says it all..

"The system relay is energized when the ignition is ON. The system relay supplies voltage to the solenoid valves and the pump motor. This voltage is referred to as the system voltage.

The electronic brake control module (EBCM) controls each solenoid valve by grounding the solenoid.

The EBCM controls the pump motor by grounding the control circuit. The pump serves 2 purposes:

• Transfers brake fluid from the brake calipers to the master cylinder reservoir during pressure decrease events.

• Transfers brake fluid from the master cylinder reservoir to the brake calipers during pressure increase events.

Conditions for Running the DTC

• The ignition voltage is greater than 10.5 volts.

• The system relay is commanded ON.

Conditions for Setting the DTC

The system voltage is less than 8 volts for 0.23 seconds.

Action Taken When the DTC Sets

If equipped, the following actions occur:

• The EBCM disables the DRP/ABS/TCS/VSES for the duration of the ignition cycle.

• The ABS indicator turns ON.

• The Traction Control indicator turns ON.

• The DIC displays the Service Stability System message.

• The EBCM will also set DTC C1248.

• The red Brake warning indicator turns ON.

Conditions for Clearing the DTC

• The condition for the DTC is no longer present and the DTC is cleared with a scan tool.

• The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Diagnostic Aids

The system relay is integral to the EBCM. The relay is not serviceable."

[Cadillac Jim]

If your car does not have ESC, the EBTCM has one relay in it. If it has ESC, it has two relays in it.

The EBTCM can be replaced by part number but even then, I have been told, it must be programmed for your car. If it is replaced by part number, it will have ESC if your car has ESC (ESC lives in the EBTCM, and the gyro and accelerometer sensor wires go to the EBTCM). Also, the RSS feeds road force data for the front wheels to the EBTCM and that information is used for traction control and ABS. The EBTCM also feeds "torque request" data to the PCM as part of the traction control function. It's possible that these signals need to be calibrated for the ESC/TC/ABS to function according to spec.

[SeaneOday]

Thank you. It is a huge help to better understand how this system works. This morning my mechanic had his scan tool hooked up and cleared these. For the first time in two weeks the lights are off.

I guess I just wait and see before trying to further diagnose?

[Cadillac Jim]

Yeah, clearing the codes does not repair anything. If the problem is a fluke, they codes won't come back. If the problem is real, then the codes will reappear, and the diagnosis will begin.

[SeaneOday]

Yeh Jim, it's a viscous cycle..!

FYI: when these codes first came up I posted about it without any response, then I looked around and read some more. I put new ceramic pads front and back, (it was almost time anyway) I inspected and used compressed air in all the leads, including to the EBTCM then leveled off the brake fluid resivoir... When I took it out for a run the lights were off on there own (without clearing) for over a week, then they just showed up again two weeks ago.

I brought the car in yesterday for a different issue and while hooked to the scan tool he cleared them. (Is that different than when I use my OBD To "clear codes"?)

** I'm about to post about yesterday's issue, an ongoing, worsening engine shudder, which we now believe to be bad crankshaft damper (harmonic balancer?) It is visibly wabbeling. Ifyou've got any input on this I'd love to hear it before I touch anything.

Thank you for your time and advice.

[Cadillac Jim]

Clearing the codes with a Tech II, from the A/C controls, or with an aftermarket code reader all do exactly the same thing. There are differences in which codes are visible and which can be cleared, but clearing a code is exactly the same no matter how it is done.

EBTCM problems can be caused by electrical problems with the connector. It's low and exposed to splash and such, particularly if the shields that go across the bottom of the car in front of, and behind, the radiator support cross-member are missing or damaged. And, if someone drops the cradle without unplugging the EBTCM, the connector can be damaged; this once caused me a lot of grief before I finally found it. Check it out first, and make sure that it has the connector clamp on it, etc.

There are people out there that will "rebuild" (replace the relays) in your EBTCM or send you one exchange for your old one. If you have trouble finding one, or you don't like the price, you might consider having yours rebuilt; that way you don't have to worry about reprogramming it.

If the damper wheel is visibly wobbling and the engine shudders at moderate or high RPM, I would venture that you do have a problem. In fact, it sounds a little scary to me. It sounds like someone damaged the damper wheel with a jack or a pylon on a lift.