Circuit Description
The throttle relaxer assembly is controlled by the electronic brake control module (EBCM) through communication with the accelerator and servo control module (ASM).
Conditions for Running the DTC
DTC 66 can be set anytime the ignition switch is in the ON position and the EBCM is attempting to change the throttle position.
Conditions for Setting the DTC
The EBCM detects maximum command current with no response from the throttle relaxer assembly
Action Taken When the DTC Sets
| • | The EBCM disables the traction control system for the remainder of the ignition cycle. |
| • | The TRAC OFF warning indicator turns ON. |
Conditions for Clearing the DTC
The condition responsible for setting the DTC no longer exists and the Scan Tool Clear DTCs function is used.
Diagnostic Aids
Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction.
The following are possible causes of the malfunction:
| • | An cruise control cable malfunction |
| • | An accelerator cable malfunction |
| • | An throttle relaxer assembly malfunction |
If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
Test Description
The numbers below refer to step numbers on the diagnostic table.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics Connector End View Reference: Antilock Brake System Connector End Views | |||
1 | Did you perform A Diagnostic System Check - ABS? | Go to Step 2 | |
Is DTC 66 set as a current DTC? | Go to Step 3 | Go to Diagnostic Aids | |
3 |
Do all the cables operate freely? | Go to Step 4 | Go to Step 5 |
4 | Check the operation of the throttle relaxer pulleys. Ensure the pulleys rotate freely. Do all the pulleys operate freely? | Go to Step 7 | Go to Step 6 |
5 | Replace the Throttle Relaxer Assembly. Refer to Accelerator and Servo Control Module Replacement . Did you complete the replacement? | Go to Step 7 | -- |
6 | Replace the appropriate cable. Refer to Accelerator Control Cable Replacement in Engine Controls - 5.7L or Cruise Control Cable Replacement in Cruise Control. Did you complete the replacement? | Go to Step 7 | -- |
7 |
Does the DTC reset? | Go to Step 2 | System OK |
