Pinpoint Test A: The Speed Control Is Inoperative
Speed Control
Pinpoint Tests
Pinpoint Test A: The Speed Control Is Inoperative
Refer to Wiring Diagrams Set 31, Speed Control for schematic and connector information. Diagrams By Number
Normal Operation
The PCM sends a signal through circuit VES10 (WH) to the speed control switches, which passes through the clockspring. The signal is grounded by the PCM circuit RES08 (GN/BN) and the clockspring. The stoplamp switch sends a voltage signal through circuit CCB08 (VT/WH) to the PCM when the brake pedal is applied, and deactivates the speed control, if engaged.
Vehicles equipped with a manual transaxle have an additional clutch pedal speed control deactivator switch. The clutch pedal speed control deactivator switch is a normally open switch with the clutch pedal released. The switch is grounded through circuit GD134 (BK/VT). When the clutch pedal is applied, the clutch pedal speed control deactivator switch moves to the closed position, which routes the ground signal through circuit CE904 (GN/VT) to the PCM, deactivating the speed control system.
The speed control deactivator switch (part of the stoplamp switch) interrupts circuit CES09 (VT/OG), removing the voltage signal to the PCM when the brake pedal is firmly applied. This is a redundant signal to the PCM.
This pinpoint test is intended to diagnose the following:
- PCM not configured for speed control
- Wiring, terminals or connectors
- Clockspring
- Digital Transmission Range (TR) sensor (automatic transaxle)
- Speed control switch
- Stoplamp switch
- Clutch pedal speed control deactivator switch (manual transaxle)
- Vehicle speed signal concern
- PCM
- ABS module
PINPOINT TEST A: THE SPEED CONTROL IS INOPERATIVE
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
-------------------------------------------------
A1 VERIFY PCM CONFIGURATION
- Enter the following diagnostic mode on the scan tool: Programmable Parameters.
- Verify that the speed control is enabled in the PCM.
- Is the speed control enabled?
Yes
GO to A2.
No
ENABLE the speed control in the PCM using the scan tool programmable parameters menu. TEST the system for normal operation.
-------------------------------------------------
A2 CHECK FOR ABS DTCs
- Review the recorded DTCs from the ABS self-test.
- Are any DTCs recorded?
Yes
REFER to Antilock Brakes / Traction Control Systems. REPAIR all ABS module DTCs and RETEST the speed control. Testing and Inspection
No
GO to A3.
-------------------------------------------------
A3 CHECK FOR PCM DTCs
- Review the recorded DTCs from the PCM self-test.
- Are any DTCs recorded?
Yes
For speed control DTCs, REFER to the DTC Charts. Diagnostic Trouble Code Tests and Associated Procedures
For all other DTCs, REFER to the Computers and Control Systems Information. REPAIR all PCM DTCs and RETEST the speed control.
No
GO to A4.
-------------------------------------------------
A4 CHECK THE VEHICLE SPEED
- Check for correct operation of the speedometer.
- Does the speedometer operate correctly?
Yes
GO to A5.
No
REFER to Instrument Panel, Gauges and Warning Indicators to continue diagnosis of the speedometer.
-------------------------------------------------
A5 CHECK THE STOPLAMP SWITCH (BOO1 AND BOO2) PIDs
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: PCM DataLogger.
- Monitor the PCM PIDs BOO1 (brake pedal top travel) and BOO2 (brake pedal bottom travel) while applying and releasing the brake pedal as follows:
- Do the PID values agree with the brake pedal positions?
Yes
If equipped with an automatic transaxle, GO to A7.
If equipped with a manual transaxle, GO to A6.
No
Go To Pinpoint Test B. Pinpoint Test B: DTC P1572 or DTC P1703
-------------------------------------------------
A6 CHECK THE CPP SWITCH (CPP_TOP) PID
- Enter the following diagnostic mode on the scan tool: PCM DataLogger.
- Monitor the PCM PID CPP_TOP while pressing and releasing the clutch pedal.
- Does the PID value agree with the clutch pedal position?
Yes
GO to A8.
No
If the CPP_TOP PID value always reads YES (engaged) GO to A9.
If the CPP_TOP PID value always reads NO (disengaged)Go To Pinpoint Test D. Pinpoint Test D: The Speed Control Does Not Disengage When The Clutch Pedal Is Applied
-------------------------------------------------
A7 MONITOR THE TR PID
- Enter the following diagnostic mode on the scan tool: Transmission Control Module (TCM) DataLogger.
- Monitor the TCM PID (TR).
- Select DRIVE.
- Does the PID value agree with the TR selector lever position?
Yes
GO to A8.
No
REFER to Transmission Control Systems to continue diagnosis of the digital TR sensor. Testing and Inspection
-------------------------------------------------
A8 CHECK THE SPEED CONTROL SWITCH
- Enter the following diagnostic mode on the scan tool: PCM DataLogger.
- Press each speed control switch while monitoring the speed control switch PID (SCCS).
- Does the PID value agree with the switch position?
Yes
GO to A10 .
No
If only one switch does not display the correct PID value, INSTALL a new speed control switch. REFER to Speed Control Switch Speed Control Switch. TEST the system for normal operation.
Otherwise, Go To Pinpoint Test C. Pinpoint Test C: DTC P0579 or DTC P0581
-------------------------------------------------
A9 CHECK THE CPP SWITCH (CPP_TOP) PID WITH THE CLUTCH PEDAL SPEED CONTROL DEACTIVATOR SWITCH DISCONNECTED
- Disconnect: Clutch Pedal Speed Control Deactivator Switch C257.
- Monitor the PCM PID CPP_TOP while pressing and releasing the clutch pedal.
- Does the PID value read NO?
Yes
INSTALL a new clutch pedal speed control deactivator switch. REFER to Speed Control Deactivator Switch Speed Control Deactivator Switch. TEST the system for normal operation.
No
REPAIR circuit CE904 (GN/VT) for a short to ground. TEST the system for normal operation.
-------------------------------------------------
A10 CHECK FOR CORRECT PCM OPERATION
- Ignition OFF.
- 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?
Yes
INSTALL a new PCM. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
-------------------------------------------------