Glow Plug Control Module Circuit High
The P0384 code means the vehicle's onboard diagnostic system has detected: Glow Plug Control Module Circuit High. This is a moderate severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- hard
- Estimated cost
- $150 - $600 (parts and labor)
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What Are the Symptoms of P0384?
- Check Engine Light on
- Glow plugs may not activate
- Hard starting in cold temperatures
- No glow plug indicator on dashboard
What Causes P0384? (Most Likely First)
- Open circuit in glow plug module wiring Very High
- Failed glow plug control module High
- Disconnected module connector Moderate
- PCM not sending control signal Low
Can I Still Drive with P0384?
Yes, but fix soon. P0384 is rated moderate severity. It is not an immediate stop-driving fault, but it will not clear itself — book the repair rather than ignoring the light.
Frequently Asked Questions
What happens when the glow plug module fails?
The glow plugs will not activate during cold starts, making the engine very difficult to start in cold weather. Once running, the engine operates normally.
Can I bypass the glow plug module?
It is not recommended. The module controls timing and duration of glow plug operation. Manual bypassing can damage glow plugs or cause a fire hazard.
How much does the glow plug module cost?
The module costs $100-$400 depending on the vehicle. Labor is typically $100-$200 for replacement.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose P0384?
-
Check module connector is fully seated.
-
Verify power and ground supply to the module.
-
Check PCM control signal to the module.
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Replace module if inputs are correct but it does not activate glow plugs.
Sources 1
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
Which Vehicles Commonly Get P0384?
- 2010-2020 Ford F-350 (6.7L Diesel)
- 2012-2019 Chevrolet Silverado 3500 (6.6L Duramax)
- 2008-2018 Ram 3500 (6.7L Cummins)
- 2011-2020 GMC Sierra 3500 (6.6L Duramax)
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