OBD Guide

P068E

Cylinder 8 Glow Plug Control Circuit Low

P068E is an OBD-II diagnostic trouble code meaning: Cylinder 8 Glow Plug Control Circuit Low. Common causes: control wire short circuit to ground, broken or damaged wiring. Estimated repair cost: $17–278.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$17–278 (est.)

Symptoms

  • Difficulty starting diesel V8 at low temperatures
  • Check Engine Light
  • White smoke on cold start
  • Unstable engine operation after starting
  • The glow plug indicator is on

Causes

  • Control wire short circuit to ground
  • Broken or damaged wiring
  • GPCM module malfunction
  • Faulty glow plug cylinder 8
  • Oxidation of connectors

How to Fix

  1. Read OBD-II codes
  2. Inspect the wiring and connectors of the cylinder 8 spark plug and GPCM
  3. Measure the voltage in the control circuit
  4. Check the spark plug resistance (normal: 0.5–2 Ohm)
  5. Check the circuit for short to ground
  6. If the circuit is working properly, diagnose and replace the GPCM

Related codes

Error P068E by Vehicle Brand

FAQ

What does the P068E code mean?

P068E is an OBD-II diagnostic trouble code that indicates: Cylinder 8 Glow Plug Control Circuit Low

What causes a P068E error code?

The most common causes of P068E include: Control wire short circuit to ground; Broken or damaged wiring; GPCM module malfunction; Faulty glow plug cylinder 8.

How do I fix a P068E diagnostic trouble code?

To fix P068E: Read OBD-II codes. Inspect the wiring and connectors of the cylinder 8 spark plug and GPCM. Measure the voltage in the control circuit. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P068E?

Yes, but get it checked soon

How much does it cost to fix P068E?

The estimated repair cost for P068E is $17–278. Actual cost depends on your vehicle, location, and labor rates.

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