Q: I have a 2000 Oldsmobile Intrigue with only 127,000 miles on it. It has been well maintained, is in very good condition and runs well. We like the car very much and would like to keep it.
However, recently several dashboard warning lights have been on and I have had a full diagnostic done which pulled up service engine codes PO122 and P1122. The recommendation is to replace the coolant temperature sensor (CTS), which is not a problem. Also, the "Brake," "ABS" and "Trac Off" warning lights are on. I quote the report: "The antilock brake system light is on with Codes P1571 and C0450 in history and B0241 and C0550 in current. The current codes will not clear using the scan tool." The recommendation is to further test the EBTCM (electronic brake traction control module) power and grounds. If C0550 is still set as current and cannot be cleared, the EBTCM needs replacement at cost of $1,200. I would not do this and would get a new car.
My question is: Rather than replacing the EBTCM, could I drive with "regular" brakes and no antilock or traction control? Various opinions have said this not not a serious problem for local driving, as "old-time" braking would still work. I am not comfortable with this. Your opinion?
A: Before answering that question, let's address the various warning lights/fault codes. Both P0122 and P1122 reference an issue with the TPS — throttle position sensor — not the CTS. The codes are the result of the powertrain control module (PCM) seeing a voltage signal less than .01 volts from the TPS for more than one second. The normal voltage output range is between 1 and 4 volts. Like the coolant sensor, the TPS is relatively inexpensive and easy to replace.
The P1571 code is set when the PCM does not see a specific "desired torque" signal from the EBTCM for more than three seconds. This code will not illuminate the "Service engine" light but will disable first-gear starts. I could not find a listing for a B0241 code but C0241 indicates the PCM is telling the EBTCM about the missing "desired torque" signal. This will disable the traction control and illuminate the "Trac Off" warning light but not the "ABS" warning light. The C0550 code illuminates when there is an internal problem with the EBTCM and illuminates the "ABS" and "Trac Off" warning lights. C0450 is set when there is an open or short circuit in the wires from the electronic power steering. It will disable the steering assist control actuator but won't illuminate the "ABS" or "Trac Off" warning lights.
Before surrendering to all this techno-jargon, find out why the "old-time" "BRAKE" warning light is on. It will illuminate primarily for two reasons — low brake fluid in the master cylinder reservoir or the parking brake switch is still engaged, perhaps due to a stuck/rusty/frozen cable. Because the "BRAKE" warning light can indicate a serious problem with the hydraulic serviced brakes, you should not drive the car until this problem is identified and corrected.
Regarding all the acronyms, if the "ABS" and "Trac Off" lights are still on after you've addressed any hydraulic issues and the "BRAKE" warning light is off, I agree that checking all connections and grounds for and between the PCM and EBTCM is the next step.
Followed by purchasing a new vehicle!
Q: I first heard a grinding sound from my 2001 Cadillac Eldorado when I backed out of my parking garage. It's a rather severe turn and I hear a grinding sound that seems to come from the steering wheel. Lately sometimes I hear it when I make a gradual turn on a city street. It doesn't happen every time I turn in my garage, but my turn is always the same way.
A: The noise is likely coming from the power steering pump. At 15 years of age the power steering fluid is probably dirty and contaminated. Have the power steering system flushed and refilled with the proper power steering fluid.
Paul Brand is the author of "How to Repair Your Car" and "How to Repair Your Truck and SUV," published by Motorbooks.