Hi guys so I have these codes c0040, c0455, p1518 need help

[Mbz03]

Hey guys trying to fix my 03 escalade I have these engine codes
c0040
c0455
P1518 any ideas and what should a replace truck has 154k on it

 

[SLCHOE]

Hey guys trying to fix my 03 escalade I have these engine codes
c0040
c0455
P1518 any ideas and what should a replace truck has 154k on it

Those codes point to 3 different issues.

First off, do you have the ability to read live data via a scan tool?

 

[Mbz03]

I have one at work

 

[SLCHOE]

I have one at work

As for c0040:

1. Verify all tires are the same size and air pressure.

2. Check the Yaw Rate Sensor, it should read 2.5 volts.

3. Check the Lateral Accelerometer, it should read 0g.

4. If ok, perform the Yaw Rate Reference Table Reset.

5. Reprogram the VSES per GM bulletin 03-05-25-005. (http://workshop-manuals.com/cadilla...traction_control_service_stability_displayed/)



As for C0455:

1. Inspect the connector at the steering wheel position sensor.

2. Monitor the steering wheel position sensor signal with a lab scope and verify a smooth sweep as steering wheel is rotated.

3. If not smooth or does not sweep as wheel is turned, verify good ground and 5 volt signal, also check the signal wire for opens or grounds. If all ok, replace the steering wheel position sensor.


As for p1518:

1. Test voltage backprobed at the throttle body.

2. If 5 volts reference at terminal E is not 4.9 to 5.1 volts test backprobed at the Throttle Actuator Control (TAC) C1 Tan connector terminal 9. Disconnect throttle body, test again.

3. Test voltage backprobed at the TAC module power and ground.

4. If disconnecting the TAC module or throttle body affected the voltages when connectors were reconnected, wiggle wires, test for poor terminal contact, loose or bent pins at the TAC module or the throttle body. Test TAC module to throttle body and PCM wires' current flow ability with a headlight.

5. Replace the TAC module.

6. Replace the throttle body.