Diagnostic Aids

WARNING: This page is about a different car, the 1995 Ford Windstar and 1995 Ford Ranger. However, it is still accessible from the selected car via links, so may be relevant.

Perform this test when instructed during QUICK TEST or if directed by other test procedures. This test is used to diagnose the following:

Wiring harness circuits (CPP and SIG RTN).
Faulty Clutch Pedal Position (CPP) switch.
Faulty Powertrain Control Module (PCM).

Fig 1: CPP Switch Test Circuit & Connector Terminal ID (Ranger & Windstar)

1) DTC P0704 & P1709: Check CPP Switch Function

These DTCs indicate CPP switch malfunction. Possible causes are as follows:

Starter relay disconnected during KOER self-test.
CPP switch circuit damage.
Faulty CPP switch.
Faulty Powertrain Control Module (PCM).

Turn ignition off. Connect scan tester to Data Link Connector (DLC). Turn ignition on. Using scan tester, access PNP PID. While observing PNP PID, apply and release clutch pedal. If PNP PID does not cycle on and off, go to next step. If PNP PID cycles on and off, check PCM connector. If connector is okay, replace PCM.

2) Check CPP Switch

Turn ignition off. Locate CPP switch near clutch pedal. Inspect switch and bracket for damage and repair if necessary. Disconnect CPP switch wiring harness connector. Measure resistance at switch terminals. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, replace CPP switch and repeat QUICK TEST.

3) Check CPP Circuit

Turn ignition off. Disconnect scan tester. Disconnect PCM 104-pin connector. Inspect pins for damage. Install EEC-V Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between test pin No. 64 (CPP) at breakout box and CPP terminal at CPP switch wiring harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open circuit and repeat QUICK TEST.

4) Leave ignition off and CPP switch disconnected. Measure resistance between chassis ground and test pins No. 64 and 91 (SIG RTN) at breakout box. If resistance is more than 10,000 ohms, replace PCM and repeat QUICK TEST. If resistance is 10,000 ohms or more, repair short circuit and repeat QUICK TEST.