OBD Guide

P1856

Transmission Transfer Case Contact Plate 'C' Short Circuit To Battery

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$17–89 (est.)

Symptoms

  • Check Engine light comes on
  • Gear shifting problems
  • Unstable all-wheel drive operation
  • The transmission goes into emergency mode
  • Reduced vehicle dynamics

Causes

  • Damage to transfer case wiring harness
  • Short circuit in contact plate circuit
  • Contact plate 'C' faulty
  • Transmission control module (TCM) problems
  • Corrosion of electrical contacts

How to Fix

  1. Check the condition of the transfer case wiring harness
  2. Diagnose contact plate circuit 'C'
  3. Check contact plate resistance
  4. Replace damaged components if necessary
  5. Test the operation of the system after repair

Related codes

Error P1856 by Vehicle Brand