Diagnostic Procedures
WARNING: This page is about a different car, the 2002 Mazda B4000, 2002 Mazda B3000, and 2002 Mazda B2300. However, it is still accessible from the selected car via links, so may be relevant.
- If QUICK TEST was not performed, go to QUICK TEST under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed, go to next step.
- Verify 4X4L Position
Verify vehicle is equipped with 4WD. Verify selector is in 4X2 or 4X4H position. If selector was in either position during QUICK TEST, go to next step. If selector was not in either position during QUICK TEST, select NEUTRAL position with shift lever. Select 4X2 or 4X4H position. Perform QUICK TEST under SELF-DIAGNOSTIC SYSTEM. - Check For Intermittent Circuit Fault
With KOEO, cycle 4X4 Shift Control Switch to 4X2. Access and observe 4X4L PID while performing the following:- Grasp vehicle wiring harness starting at transfer case harness connector. Shake and bend a small section of harness, continuing to PCM.
- Tap vehicle harness connector at transfer case.
- Shake and bend a small section of harness between instrument cluster connector and PCM.
- Check 4X4L Signal From Module
Turn ignition off. Disconnect PCM connector. Install breakout box, leave PCM disconnected. With KOEO, measure voltage between breakout box terminals No. 68 (4X4L circuit) and 24 (PWR GND circuit) while cycling 4X4 Shift Control switch. If voltage cycles, replace faulty PCM. Go to step 7 . If voltage does not cycle, go to next step.NOTE: Wire color for 4X4L circuit is not available from manufacturer. - Check Resistance Of 4X4L Wire
Turn ignition off. Disconnect GEM module. Measure resistance of 4X4L circuit between breakout box terminals No. 68 (4X4L circuit) and 4X4 Shift Control switch harness connector. See Fig 1 or Fig 2 F. Resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open circuit. See WIRING DIAGRAMS article. Go to step 7 . - Check For Short To Power & Ground
Reconnect GEM module. Measure resistance between breakout box terminals No. 68 (4X4L circuit) and 24/103 (VPWR circuit). Record reading. Measure resistance between breakout box terminals No. 68 (4X4L circuit) and 71/97 (VPWR circuit). Record reading. If each resistance is more than 10,000 ohms, see appropriate DIAGNOSIS article in TRANSFER CASES. If either resistance is 10,000 ohms or less, repair short circuit. See WIRING DIAGRAMS article. Go to next step. - Verify Trouble Shooting Of DTCs Completed
Reconnect all electrical connectors. Using scan tool, clear DTC memory. Using scan tool, retrieve DTCs. See QUICK TEST under SELF-DIAGNOSTIC SYSTEM. If same DTC is present, replace faulty PCM and repeat QUICK TEST under SELF-DIAGNOSTIC SYSTEM. If any other DTC is present, go to applicable procedure for other DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no DTCs are set, trouble shooting is complete.