Glow Plug Control Module Circuit Low
The P0383 code means the vehicle's onboard diagnostic system has detected: Glow Plug Control Module Circuit Low. 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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Common Symptoms
- Check Engine Light on
- Extended crank time in cold weather
- Glow plug indicator stays on too long or not at all
- White smoke on startup
Probable Causes (Ranked by Likelihood)
- Short to ground in glow plug module wiring Very High
- Failed glow plug control module High
- Corroded module connector Moderate
- PCM communication circuit fault Low
Frequently Asked Questions
What is the glow plug control module?
It is an electronic module that controls when and how long the glow plugs operate. It receives commands from the PCM and activates the glow plugs accordingly.
Can a bad module damage glow plugs?
Yes, a malfunctioning module can over-energize glow plugs, causing them to burn out prematurely or overheat.
Where is the glow plug control module?
It is typically mounted on the engine near the glow plugs. On Ford diesels, it is on the passenger side valve cover area.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
-
Check glow plug control module connector for corrosion or damage.
-
Measure control module supply voltage and ground.
-
Check communication wiring between PCM and glow plug module.
-
Replace module if wiring tests good.
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)
Commonly Affected Vehicles
- 2010-2020 Ford F-250 (6.7L Diesel)
- 2012-2019 Ram 2500 (6.7L Cummins)
- 2008-2018 Chevrolet Silverado 2500 (6.6L Duramax)
- 2011-2020 GMC Sierra 2500 (6.6L Duramax)
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