Test TG: 4WD Low Indicator Circuits (Explorer & Mountaineer)
WARNING: This page does not describe the selected car, but rather 13 other vehicles, including the 2003 Mazda B4000, 2003 Mazda B3000, 2003 Mazda B2300, 2002 Mazda B4000, and 2002 Mazda B3000. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
After each service or repair procedure has been completed, reconnect all components. Clear DTCs and repeat QUICK TEST. See RETRIEVING DIAGNOSTIC TROUBLE CODES (QUICK TEST) under SELF-DIAGNOSTIC SYSTEM. Ensure all EEC-V systems are working properly and DTCs are no longer present.
Perform this test when instructed during QUICK TEST or if directed by other test procedures. This test is used to diagnose the following:
- Generic Electronic Control Module Wiring Harness Circuits.
- Faulty PCM.
- DTC P1729 indicates open or short in 4X4 switch circuit. DTC P1781 indicates 4X4L switch position closed during QUICK TEST. If switch position was not 4X2 or 4X4H during KOEO SELF-TEST, select 4X2 or 4X4H and repeat QUICK TEST. See RETRIEVING DIAGNOSTIC TROUBLE CODES (QUICK TEST) under SELF-DIAGNOSTIC SYSTEM. If switch position was as specified, go to next step.
- Using NGS tester, select 4X4L PID. Turn ignition switch to ON position. Cycle 4X4L switch to 4X2. Check for indication of fault while performing the following: Wiggle and bend small sections of wiring harness starting at transfer case working toward PCM. Lightly tap on transfer case wiring harness connector. Wiggle and bend small sections of wiring harness starting at instrument cluster working toward PCM. Fault will be indicated by PID value changing (ON/OFF). If any faults are found, isolate fault and repair as necessary. If no faults are found, go to next step.
- Turn ignition switch to OFF position. Disconnect PCM 104-pin connector. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Turn ignition switch to ON position. While cycling 4X4L switch, measure voltage between chassis ground and PCM connector terminal No. 14 (Light Blue/Black wire). See Figure. If voltage cycles, replace PCM. If voltage does not cycle, go to next step.
- Turn ignition switch to OFF position. Disconnect GEM 22-pin Black harness connector C282. GEM is located behind center of dash. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Measure resistance of Light Blue/Black wire between PCM connector terminal No. 14 and GEM 22-pin Black harness connector C282 terminal No. 10. See Fig 1 and Figure . If resistance is 5 ohms or less, go to next step. If resistance is more than 5 ohms, repair open in Light Blue/Black wire between PCM and GEM.
- Reconnect GEM 22-pin Black harness connector C282. Measure resistance between PCM connector terminal No. 14 and negative battery terminal. Measure resistance between PCM connector terminals No. 14 (Light Blue/Black wire) and No. 71 (Red wire). See Figure. If both resistance measurements are more than 10 k/ohms, 4X4L circuit is okay. Check transfer case for mechanical fault. If either resistance measurement is 10 k/ohms or less, repair short in Light Blue/Black wire.