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Accessory Switch Transfer Case Mode Indicator Flashes In Neutral Mode



Accessory Switch Transfer Case Mode Indicator Flashes in Neutral Mode

Circuit Description
The Isuzu T150 transfer case contains a neutral switch, which is supplied battery voltage by the transfer case shift control module. When the transfer case mode selection is in neutral the neutral switch provides a path to ground pulling the neutral signal circuit low. This assists the transfer case shift control module in determining the present mode. A fault in the 2WD/4WD signal circuit, or the neutral switch signal circuit will cause the neutral mode indicator to flash. A fault in the front axle actuator or the corresponding front axle actuator circuits can also cause the neutral mode indicator to flash.

Diagnostic Aids
^ Check the inline connector C105 for proper connection, bent pins, damage, or corrosion. Refer to Harness Routing Views.
^ Check the transfer case shift control module connectors C1 and C2 for proper connection and bent or corroded pins or terminals. Refer to Repairing Connector Terminals.Diagnostic Aids
^ Check for water leaks at doors and bulkhead areas. Refer to Waterleak Test Preparation.
^ Check the Neutral switch for proper connection, bent pins, or damaged terminals. Refer to Transfer Case Control Component Views.

Test Description
The number below refers to the step number on the diagnostic table.
2. This step determines if the front axle actuator is causing the symptom.
4. This step determines if the neutral switch is causing the symptom.
5. This step determines if an open neutral signal circuit is causing the symptom.
6. This step determines if a shorted to ground 2WD/4WD switch signal circuit is causing the symptom.

Step 1 - Step 9: