OBD Guide

P1718

Automatic Transmission CAN Communication Circuit

Severity
🔴 High
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$6–56 (est.)

Symptoms

  • Incorrect gear shifting
  • The gearbox goes into emergency mode
  • Check Engine light comes on
  • Reduced vehicle dynamics
  • Possible jerking when changing gears

Causes

  • Open or short circuit in the CAN bus
  • Damage to the automatic transmission wiring harness
  • Malfunction of the automatic transmission control unit
  • Problems with CAN bus power supply
  • Corrosion of contacts in connectors

How to Fix

  1. Check the integrity of the CAN bus wiring
  2. Inspect the connectors and contacts of the automatic transmission control unit
  3. Check the CAN bus supply voltage
  4. Scan other modules for communication errors
  5. If necessary, replace damaged wires or connectors

Related codes

Error P1718 by Vehicle Brand