P0670 on 2007-2019 GMC Sierra 3500HD — Glow Plug Module Control Circuit
1 vehicles · 1 makes · $250-$1,200 repair
Most Reported On
P0670 is an OBD-II diagnostic trouble code meaning “Glow Plug Module Control Circuit.” This code indicates the engine computer detected a fault in the control circuit between the PCM and the glow plug control module on a diesel engine. The glow plug module energizes the glow plugs to preheat the cylinders for cold starting. A fault here mainly causes hard cold starts, rough cold-start running, and white smoke until the engine warms up. This code is most commonly reported on 2007-2019 GMC Sierra 3500HD, with repair costs ranging from $250 to $1,200.
Common Causes
Typical Repair Cost
Based on 1 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose P0670, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
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FAQ
What does P0670 mean?
P0670 stands for "Glow Plug Module Control Circuit." This code indicates the engine computer detected a fault in the control circuit between the PCM and the glow plug control module on a diesel engine. The glow plug module energizes the glow plugs to preheat the cylinders for cold starting. A fault here mainly causes hard cold starts, rough cold-start running, and white smoke until the engine warms up.
What are the most common causes of P0670?
The most common causes of P0670 are: Faulty glow plug control module, Open or shorted wiring between PCM and glow plug module, Corroded or loose module connectors, Blown fuse feeding the glow plug system, Poor ground at the module, PCM control circuit fault. The specific cause varies by vehicle.
How much does it cost to fix P0670?
Repair costs for P0670 range from $250 to $1,200, depending on the vehicle and root cause.
Which vehicles are affected by P0670?
Au7o has documented P0670 across 1 vehicle models from 1 manufacturers: GMC.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.