OBD Guide

P18C2

Internal Mode Switch 'P' Circuit Stuck On Invalid Voltage Range

P18C2 is an OBD-II diagnostic trouble code meaning: Internal Mode Switch 'P' Circuit Stuck On Invalid Voltage Range. Common causes: malfunction of the internal mode switch, open or short circuit in switch circuit. Estimated repair cost: $17–89.

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

Symptoms

  • Inability to start the engine in 'P' position
  • Incorrect display of current transmission mode
  • Selector lever position indicator flashing
  • The Check Engine light comes on
  • Problems with switching transmission modes

Causes

  • Malfunction of the internal mode switch
  • Open or short circuit in switch circuit
  • Poor contact in wiring connectors
  • Wiring harness damage
  • Transmission control module (TCM) malfunction

How to Fix

  1. Check the integrity of the wiring and connectors of the switch circuit
  2. Check the voltage at the mode switch
  3. Test the operation of the internal mode switch
  4. If necessary, replace the mode switch
  5. Check and, if necessary, replace the transmission control module

Related codes

FAQ

What does the P18C2 code mean?

P18C2 is an OBD-II diagnostic trouble code that indicates: Internal Mode Switch 'P' Circuit Stuck On Invalid Voltage Range

What causes a P18C2 error code?

The most common causes of P18C2 include: Malfunction of the internal mode switch; Open or short circuit in switch circuit; Poor contact in wiring connectors; Wiring harness damage.

How do I fix a P18C2 diagnostic trouble code?

To fix P18C2: Check the integrity of the wiring and connectors of the switch circuit. Check the voltage at the mode switch. Test the operation of the internal mode switch. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P18C2?

Limited driving only, diagnose soon

How much does it cost to fix P18C2?

The estimated repair cost for P18C2 is $17–89. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat