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P0751 OD Off Switch Pressed (LO) More Than 5 Minutes

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Mopar1973Man

By Mopar1973Man

DTC P0751: OD OFF SWITCH PRESSED (LO) MORE THAN 5 MINUTES

Circuit Description

Circuit is monitored after engine is running for 10 seconds and reviewed every 440 ms. DTC sets if overdrive switch is held low for 5 minutes or more from time of closure or ignition on.

Possible Cause

The following items may be area of concern:

  • Intermittent OD OFF switch fault.
  • OD OFF switch sense circuit shorted to ground.
  • OD OFF switch defective.
  • PCM defective.

Diagnostic Procedure

1. Using scan tool, read DTCs. If good trip counter for DTC P0751 is not displayed or displayed count is not zero, go to step 4 . If good trip counter is displayed and displayed count is zero, go to next step.

2. Turn ignition off. Disconnect PCM harness connectors. Disconnect OD OFF switch harness connector. Inspect connectors and terminals for damage. Repair as necessary. Measure resistance between ground and OD OFF switch sense circuit at PCM harness connector C3 (Gray) terminal No. 13. If resistance is less than 5 ohms, repair OD OFF switch sense circuit for short to ground. If resistance is 5 ohms or more, go to next step.

3. Measure resistance between ground and OD OFF switch sense circuit at PCM harness connector C3 (Gray) terminal No. 13 while pressing OD OFF switch. Resistance should change from more than 5 ohms to less than 5 ohms when switch is pressed. If resistance is as specified, replace PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. If resistance is not as specified, replace OD OFF switch. See REMOVAL & INSTALLATION in appropriate SERVICING article in AUTOMATIC TRANSMISSIONS.

4. Conditions required to set DTC are not currently present. Inspect all applicable connectors and terminals for damage. Repair as necessary. If connectors and terminals are okay, see INACTIVE DTC CONDITION under SELF-DIAGNOSTIC SYSTEM. Testing is complete.

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