OBD Guide

P1878

Transmission Transfer Case Disengaged Solenoid Circuit Failure

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$28–89 (est.)

Symptoms

  • Check Engine Light Is On
  • Problems with switching all-wheel drive modes
  • The car goes into emergency mode
  • Reduced vehicle dynamics
  • Possible jerking when moving

Causes

  • Open or short circuit in solenoid circuit
  • Transfer case solenoid malfunction
  • Solenoid relay problems
  • Transmission control unit malfunction
  • Poor contact in wiring connectors

How to Fix

  1. Diagnostics of the solenoid circuit with a multimeter
  2. Checking Solenoid Resistance
  3. Inspect wiring and connectors for damage
  4. Replacing a faulty solenoid
  5. Resetting the error code and checking the system

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