Pinpoint Test A: The Speed Control Is Inoperative: Testing
WARNING: This page is about a different car, the 2005 Mercury Montego, 2005 Ford Freestyle, and 2005 Ford Five Hundred. However, it is still accessible from the selected car via links, so may be relevant.
- A1 CHECK FOR DTCs
- Review the recorded DTCs from the powertrain control module (PCM) self-test.
- Are any DTCs recorded?
- Yes : REFER to the POWERTRAIN CONTROL MODULE DIAGNOSTIC TROUBLE CODE INDEX .
- No : GO to A2.
- A2 CHECK THE SPEED CONTROL SWITCH
- Disconnect: PCM C175b.
- Measure the resistance between the PCM C175b-19, circuit 848 (DG/OG), harness side and the PCM C175b-30, circuit 151 (LB/BK), harness side while pressing the speed control switch buttons as follows:SPEED CONTROL SWITCH RESISTANCE REFERENCE
Speed Control Switch Resistance Value OFF Less than 5 ohms CANCEL 110 - 130 ohms SET- 276 - 324 ohms SET+ 552 - 648 ohms RESUME 1,021 - 1,199 ohms ON 1,941 - 2,278 ohms No switch pressed 3,965 - 4,655 ohms - Are the speed control switch resistance values OK?
- Yes : GO to A3.
- No : INSTALL a new speed control switch. REFER to SPEED CONTROL SWITCH . CLEAR the DTCs. REPEAT the self-test.
- A3 MONITOR THE TRANSMISSION RANGE PID
- Connect: PCM C175b.
- Key in ON position.
- Enter the following diagnostic mode on the diagnostic tool: PID Data Monitor and Record.
- Monitor the transmission range PID.
- Select DRIVE.
- Does the PID value agree with the transmission range selector lever position?
- Yes : GO to A4.
- No : REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - CVT or AUTOMATIC TRANSAXLE - 6 SPEED .
- A4 CHECK THE PARKING BRAKE WARNING INDICATOR
- Key in ON position.
- While observing the parking brake warning indicator, apply and release the parking brake.
- Does the parking brake warning indicator operate correctly?
- Yes : GO to A5.
- No : REFER to INSTRUMENT CLUSTER to diagnose the parking brake warning indicator.
- A5 CHECK THE VEHICLE SPEED NOTE: This step may require an assistant.
- Enter the following diagnostic mode on the diagnostic tool: Anti-lock Brake System (ABS) Wheel Speed PID.
- Monitor and record the ABS module wheel speed PID while driving the vehicle at 48 km/h (30 mph) as indicated on the speedometer.
- Enter the following diagnostic mode on the diagnostic tool: PCM Vehicle Speed PID.
- Monitor and record the PCM vehicle speed PID while driving the vehicle at 48 km/h (30 mph).
- Does the speed indicated by the ABS module wheel speed PID match the PCM vehicle speed PID?
- Yes : GO to A6.
- No : REFER to the INTRODUCTION - GASOLINE article to diagnose the output shaft sensor (OSS) signal.
- A6 CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Check for:
- corrosion
- pushed-out pins
- Connect all the PCM connectors and make sure they are seated correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
- Yes : INSTALL a new PCM. REFER to ELECTRONIC ENGINE CONTROLS . CLEAR the DTCs. REPEAT the self-test.
- No : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.