Diagnostic Procedure
DIAGNOSTIC INFORMATION AND PROCEDURES CHART (AXLE LOCK INDICATOR PROBLEMS)
| TEST | ACTION | APPLICABILITY |
|---|---|---|
| 1 |
NOTE:
The following tests are to diagnose an inoperative Axle Lock indicator. If the Axle Lock indicator flashes, the Enable conditions have not been met to lock the axle, or an axle mechanical fault exists.
NOTE:
The Front Axle Lock and Rear Axle Lock indicators can NOT be diagnosed using the Instrument Cluster self test. With the DRBIII®, read DTCs.Are any ABS, PCM, VSS, or Transfer Case DTCs present?Yes --> Refer to DRIVEABILITY or TRANSMISSION/TRANSFER CASE diagnostics information for the related symptom(s).Perform BODY VERIFICATION TEST - VER 1 .No --> Go To 2 |
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| 2 | Select the inoperative indicator. Rear Axle Lock Indicator Go To 3 Front Axle Lock Indicator Go To 8 |
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| 3 | Perform the Axle Locker test . Turn the ignition on. Place transfer case in 4WD Lo and visually confirm by observing the 4WD indicator. Drive the vehicle at less than 10 MPH (16 km/h). Press the Axle Lock switch once. Did the Rear Axle Lock indicator illuminate? Yes --> The condition is not present at this time. Monitor DRBIII® parameters while wiggling the related wire harness. Refer to any Technical Service Bulletins (TSBs) that may apply. Visually inspect the related wiring harness and connector terminals. Perform BODY VERIFICATION TEST - VER 1 . No --> Go To 4 |
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| 4 | Place the transfer case in 4WD Lo. Drive the vehicle at less than 2.5 MPH (4 km/h). With the DRBIII® in Inputs/Outputs, read the Enable 1 state, (should read LOW). With the DRBIII® in Inputs/Outputs, read the Rear Lock Request state. Press the Axle Lock switch once. Did the Rear Lock Request change state? Yes --> Replace and configure the Instrument Cluster in accordance with the Service Information. Perform BODY VERIFICATION TEST - VER 1 . No --> Go To 5 |
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| 5 | Turn the ignition off. Disconnect the Axle Lock Switch harness connector. Measure the voltage between the Fused B(+) circuit and ground. Is the voltage below 10.5 volts? Yes --> Repair the Axle Locker Switch Fused B(+) circuit for an open. Perform BODY VERIFICATION TEST - VER 1 . No --> Go To 6 |
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| 6 | Turn the ignition off. Disconnect the Axle Lock Switch harness connector. Measure the resistance between ground and the Axle Locker Switch Ground circuit. Is the resistance above 5.0 ohms? Yes --> Repair the Axle Locker Switch Ground circuit for an open. Perform BODY VERIFICATION TEST - VER 1 . No --> Go To 7 |
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| 7 | Turn the ignition off. Disconnect the Axle Locker Switch harness connector. Disconnect the Instrument Cluster C1 harness connector. Measure the resistance of the Rear Locker Request circuit between the Axle Locker Switch connector and the Instrument Cluster C1 connector. Is the resistance above 5.0 ohms? Yes --> Repair the Rear Locker Request circuit for an open. Perform BODY VERIFICATION TEST - VER 1 . No --> Replace the Axle Lock Switch in accordance with the Service Information. Perform BODY VERIFICATION TEST - VER 1 . |
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| 8 | Place transfer case in 4WD Lo and drive vehicle at less than 2.5 MPH (4 km/h). Press the Axle Locker Switch once to lock the rear axle. With the DRBIII® in Inputs/Outputs, ensure that the Enable 1 and Enable 2 states both read LOW. With the DRBIII® in Inputs/Outputs, ensure that the Rear Lock Request and Rear Lock Return states both read LOCKED. Press the Axle Locker Switch again. Did the Front Axle Lock indicator illuminate? Yes --> The condition is not present at this time. Monitor DRBIII® parameters while wiggling the related wire harness. Refer to any Technical Service Bulletins (TSBs) that may apply. Visually inspect the related wiring harness and connector terminals. Perform BODY VERIFICATION TEST - VER 1 . No --> Go To 9 |
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| 9 | Place the vehicle in 4WD Lo, operate vehicle at 2.5 MPH (4 km/h) or less. With the DRBIII® in Inputs/Outputs, ensure that the Enable 1 and Enable 2 states read LOW. The Rear Axle Lock indicator must be illuminated. With the DRBIII® in Inputs/Outputs, read the Front Lock Request state. Press the Axle Locker Switch. Did the Front Axle Lock Request change state? Yes --> Replace and configure the Instrument Cluster in accordance with the Service Information. Perform BODY VERIFICATION TEST - VER 1 . No --> Go To 10 |
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| 10 | Turn the ignition off. Disconnect the Axle Locker Switch harness connector. Disconnect the Instrument Cluster C2 harness connector. Measure the resistance of the Front Locker Request circuit between the Axle Locker Switch connector and the Instrument Cluster C2 connector. Is the resistance above 5.0 ohms? Yes --> Repair the Front Locker Request circuit for an open. Perform BODY VERIFICATION TEST - VER 1 . No --> Replace the Axle Lock Switch in accordance with the Service Information. Perform BODY VERIFICATION TEST - VER 1 . |
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