CX28 Transmission For Combat and Tactical Vehicles Transmission ; Transfer Case Electronic Control System Caterpillar

Disconnect the detent switch connector. Use an Ohm Meter to check the resistance between pins 1 and 2 on the detent switch. With the engine idling change the transfer case from high range to low range.

The possible causes of this are:

• Bad detent switch

• Debris in plunger groove

• Bad harness

• Bad ECM

Results:

• Ok - The detent switch will indicate Open (high resistance) when in high range and shorted (low resistance) when in low range. STOP

Test Step 2. Detent Switch Test - Manual

1. Remove detent switch from Transfer Case

2. Leave switch connected to transfer case harness

3. Repeat the resistance check while actuating the switch manually.

Results:

• OK - Resistance Changes, Switch, and transfer case harness are OK.

• Not Ok - Resistance dose not change

  Repair: Replace switch or harness components. Repeat detent switch test-manual

Test Step 3. Detent Plunger Test

Remove and inspect detent plunger for debris in detent switch groove

Results:

• Ok - No debris in detent switch groove.STOP

• Not Ok - Debris in Groove. Clean detent plunger and reinstall, with switch installed, repeat resistance check

Test Step 4. With Functional Switch, Harness, and Clean Detent Plunger Installed – Repeat Resistance Check

Results:

• OK Detent switch resistance changes with transition from high to low range - STOP

• Not Ok Detent switch resistance does not change after inspection and cleaning -

  Repair: Transfer Case must have mechanical inspection/repair

  STOP