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P1840 Ford Code - Transfer Case Shift Motor Short Circuit To Battery

- Code Popularity: 4,457 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
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What are the Possible Causes of the DTC P1840 Ford?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Faulty Transfer Case Control Module (TCCM)
  • Transfer Case Control Module harness is open or shorted
  • Transfer Case Control Module circuit poor electrical connection
  • Faulty Transfer case
  • Faulty Front axle assembly
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How to Fix the DTC P1840 Ford?

Review the 'Possible Causes' mentioned above and visually examine the corresponding wiring harness and connectors. Ensure to check for any damaged components and inspect the connector pins for signs of being broken, bent, pushed out, or corroded.

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What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P1840 Ford code, it typically requires 1.0 hour of labor. The specific diagnosis time and labor rates at auto repair shops can differ based on factors such as the location, make and model of the vehicle, and even the engine type. It is common for most auto repair shops to charge between $75 and $150 per hour.

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)

Code P1840 Ford Description

The Mode Select Switch (MSS) communicates the operator's choice to the Transfer Case Control Module (TCCM). As the TCCM commands the gearmotor encoder assembly to 4H mode, the transfer case shift fork moves to engage 4H mode which also engages the dual-cone synchronizers to bring the front driveline to the same speed as the rear driveline. The TCCM also activates the hublock vacuum solenoid, providing a vacuum and engaging the Constant Vacuum Hublock (CVH) at each front wheel. If the vehicle is not responding to the operator's intentions, systematically check the necessary inputs and outputs of the TCCM, components of the transfer case, CVH components, and axle shafts. Check all circuits for opens and shorts to power or ground.

OBDII Code P1840 Ford - Transfer Case Shift Motor Short Circuit To Battery - AutoCodes.com
P1840 Ford Code - Transfer Case Shift Motor Short Circuit To Battery

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