Pinpoint Test D: The Speed Control Does Not Disengage When The Clutch Is Applied

WARNING: This page is about a different car, the 2007 Lincoln Mark LT and 2007 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

D1 CHECK THE PCM CPP SWITCH PID
- Key in ON position.
- Enter the following diagnostic mode on the diagnostic tool: PCM CPP Switch PID
- Monitor the PCM CPP_TOP PID while pressing and releasing the clutch pedal.
- Does the PCM CPP_TOP PID agree with the clutch pedal position?
1. YES : Go to D3.
2. NO : Go to D2.
D2 CHECK CIRCUIT 306 (TN/LB) FOR A SHORT TO GROUND
- Key in OFF position.
- Disconnect: PCM C175b
- Disconnect: CPP Switch C257
- Measure the resistance between the PCM C175b-38, circuit 306 (TN/LB), harness side and ground.
  
  Fig 1: Checking Circuit 306 (TN/LB) For Short To Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance greater than 10,000 ohms?
1. YES : INSTALL a new CPP switch. REFER to ELECTRONIC ENGINE CONTROLS article. TEST the system for normal operation.
2. NO : REPAIR the circuit. TEST the system for normal operation.
D3 CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Check for:
  - corrosion
  - damaged pins
  - pushed-out pins
- Connect all the PCM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
1. YES : INSTALL a new PCM. REFER to ELECTRONIC ENGINE CONTROLS article. TEST the system for normal operation.
2. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.