Diagnostic Aids

WARNING: This page does not describe the selected car, but rather 26 other vehicles, including the 1999 Mercury Tracer, 1999 Mercury Sable, 1999 Mercury Mystique, 1999 Mercury Mountaineer, and 1999 Mercury Grand Marquis. However, it is still accessible from the selected car via links, so may be relevant.

Enter this test when directed by QUICK TEST. This test is only intended to diagnose:

Harness circuit (GLI).
Powertrain Control Module (PCM).

1) DTCs P1244, P1245 Of P1246

Check generator belt condition and tension. Ensure battery is fully charged. Check charging system and repair as necessary. If charging system is okay, go to next step.

2) Check For Short To Power

Turn ignition off. Disconnect voltage regulator connector. Disconnect PCM 104-pin connector. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Turn ignition on. Measure voltage between PCM connector pin No. 59 and ground. If voltage is less than one volt, go to next step. If voltage is one volt or more, repair short to power in GLI circuit.

3) Check For Short To Ground

Turn ignition off. Disconnect scan tool from Data Link Connector (DLC). Measure resistance between PCM connector pin No. 59 and ground. If resistance is more than 10,000 ohms, go to next step. If resistance is 10,000 ohms or less, repair short to ground in GLI circuit.

4) Check For Open Circuit

Measure resistance of GLI circuit between PCM connector pin No. 59 and GLI circuit terminal at voltage regulator wiring harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in GLI circuit.

5) Check PCM

Reconnect PCM connector. Turn ignition on. Measure voltage between GLI circuit terminal at voltage regulator wiring harness connector and ground. If voltage is more than 2 volts, GLI circuit is okay. Check charging system and repair as necessary. If voltage is 2 volts or less, replace PCM.