Well I went out and bought a Actron CP9850 which is a pretty sweet code reader and has some nice datalogging abilities.

I updated it with the latest version and plugged her in and pulled a few codes.

C0035 - Left Front Wheel Speed Circuit Malfunction
C0040 - Right Front Wheel Speed Circuit Malfunction
C0281 - Brake Switch Circuit
C0240 - PCM Traction Control Not Allowed
C0242 - PCM Indicated TCS Malfunction



I'm wondering if the front two speed sensors are broken or have a bad connection to the PCM/EBCM which is causing the TCS malfunctions along with the reduced power mode. The car was running fine today so I'm going to keep the scanner with me and if the REP comes back on I'm going to pull the codes that show up. I may run some datalogging while driving as well to see what happens.

Any ideas or inputs are welcome. Not sure if this was worth the $200 but it's a pretty handy tool so far.

 

Good to know that you can read ABS codes with that unit.

What kind of brake problems were you having that made you get it so you could read the DTC's???

Bob

 

Kept going into reduced power mode. Still does sometimes.

 

Does your code reader show the two characters following the DTC codes? Here are what the two characters are for those two codes and what they mean.

DTC C0035 00 : Left Front Wheel Speed Sensor Circuit

DTC C0035 0F : Left Front Wheel Speed Sensor Circuit Erratic Signal

DTC C0035 18 : Left Front Wheel Speed Sensor Circuit Signal Amplitude Less Than Minimum

DTC C0040 00 : Right Front Wheel Speed Sensor Circuit

DTC C0040 0F : Right Front Wheel Speed Sensor Circuit Erratic Signal

DTC C0040 18 : Right Front Wheel Speed Sensor Circuit Signal Amplitude Less Than Minimum

C0035-C0050 18
The code is set when the following conditions exist:
• One wheel speed is 0 km/h.
• The remaining wheel speeds are greater than 8 km/h (5 mph).
• The difference between the remaining wheel speeds is less than 11 km/h (7 mph) from each sensor.
C0035-C0050 0F
The code is set when both of the following conditions exist:
• The EBCM detects a change in wheel speed that exceeds 20 km/h (12 mph) between two 10 millisecond wheel speed samples.
• The condition occurs 3 times in 200 milliseconds.
C0035-C0050 00
The code is set when either of the following conditions exist:
• An open or a short to ground is detected on the wheel speed sensor signal circuit by the EBCM.
• A short to voltage is detected on the wheel speed sensor signal circuit by the EBCM.

Bill

 

Not that I noticed. I'm going to first check the wiring and see if there's a short somewhere. I figured since both sensors where going bad I needed to check if there was a common ground for both of them. Otherwise it may be that both have an actual issue with each. When the car goes into REP again I'm going to hook up the reader and see what I can pull with the REP active. Thanks for the info Bill.