Test A: No Communication With Generic Electronic Module
WARNING: This page is about a different car, the 2002 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
After repair, clear DTCs and retest system.
- Connect New Generation Star (NGS) tester to Data Link Connector (DLC). DLC is located below driver's side instrument panel, right of steering column. Using NGS tester, monitor Generic Electronic Module (GEM) PID IGN_GEM while turning ignition switch through all positions. Depress clutch pedal when turning ignition switch to START position (M/T). If PID values agree with ignition switch positions, go to next step. If PID values do not agree with ignition switch positions, repair appropriate ignition switch circuit as necessary. See POWER DISTRIBUTION in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
- Turn ignition switch to LOCK position. Disconnect central junction box 34-pin harness connector C270b. Measure voltage between ground and central junction box harness connector C270b terminal No. 11 (Tan/Black wire). See Fig 1. If battery voltage exists, go to next step. If battery voltage does not exist, repair open in Tan/Black wire between battery junction box and central junction box. See POWER DISTRIBUTION in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
- Disconnect GEM from central junction box 18-pin internal connector C201d. Connect central junction box harness connector C270b. Measure voltage between ground and central junction box internal connector C201d terminal No. 4 (central junction box side). Measure voltage between ground and internal connector C201d terminal No. 16 (central junction box side). See Fig 1. If battery voltage exists at both terminals, go to next step. If battery voltage does not exist at one or both terminals, replace central junction box. See CENTRAL JUNCTION BOX under REMOVAL & INSTALLATION.
- Disconnect central junction box 34-pin harness connector C270b. Measure internal resistance of central junction box between C270b terminal No. 11 (central junction box side) and internal connector C201d terminal No. 4 (central junction box side). Measure internal resistance of central junction box between harness connector C270b terminal No. 11 (central junction box side) and internal connector C201d terminal No. 16 (central junction box side). See Fig 1. If each resistance is 5 ohms or less, go to next step. If either resistance is more than 5 ohms, replace central junction box. See CENTRAL JUNCTION BOX under REMOVAL & INSTALLATION.
- Disconnect GEM 26-pin harness connector C201a. Measure resistance between ground and GEM harness connector C201a terminal No. 26 (Black/Light Blue wire). See Fig 2. If resistance is 5 ohms or less, go to next step. If resistance is more than 5 ohms, repair open in Black/Light Blue wire between GEM and ground. Ground is located behind left kick panel. See WIRING DIAGRAMS .
- Measure resistance between ground and GEM harness connector C201a terminal No. 14 (Black/Light Blue wire). See Fig 2. If resistance is 5 ohms or less, repair module communications problem. See MODULE COMMUNICATIONS NETWORK - F150 PICKUP article. If resistance is more than 5 ohms, repair open in Black/Light Blue wire between GEM and ground. Ground is located behind left kick panel. See WIRING DIAGRAMS .