Basic checks
Veepeak OBDCheck BLE
A Bluetooth LE adapter for reading standard engine codes and supported live data.
View on AmazonP0670
Glow Plug Module Control Circuit
Moderate severity
The control circuit between the engine controller and the glow plug control module reports a fault. The ECU can no longer reliably command the module that drives the glow plugs, so cold-start pre-heating may not run. On a diesel this causes hard starting, white smoke, and rough running until warm. Causes: open or shorted wiring between ECU and glow plug module, a failed module, or a power/ground fault at the module.
The control circuit between the engine controller and the glow plug control module reports a fault. The ECU can no longer reliably command the module that drives the glow plugs, so cold-start pre-heating may not run. On a diesel this causes hard starting, white smoke, and rough running until warm. Causes: open or shorted wiring between ECU and glow plug module, a failed module, or a power/ground fault at the module.
Common causes
- high
Glow plug control module faulty
One of the most commonly reported causes for this code — check this first.
Typical part cost: $170-770
- medium
Wiring or connector fault
A plausible cause — test and verify before replacing parts.
Typical part cost: $170-770
See all causes + fix costs
Create a free Wrenchify account to unlock the rest for P0670.
Unlock causesFree forever · No credit card
First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
Get the full step-by-step diagnosis
Create a free Wrenchify account to unlock the rest for P0670.
Unlock diagnosisFree forever · No credit card
Tools you may need
Already have a compatible scanner? Use it. If not, a Bluetooth OBD2 adapter can help you confirm engine codes and check supported live sensor data before replacing parts.
Regular diagnostics
vgate iCar Pro BLE 4.0
A Bluetooth LE adapter with an automatic sleep feature for routine code and sensor checks.
View on AmazonAnother option
OBDLink CX
A Bluetooth LE adapter to consider when comparing supported vehicles and diagnostic apps.
View on AmazonIllustrations shown, not product photos. Check vehicle, phone and app compatibility before buying. These adapters do not guarantee access to ABS, airbags or manufacturer-specific systems. Clearing a code does not repair the fault and can reset emissions readiness monitors.
As an Amazon Associate, Wrenchify earns from qualifying purchases. This supports the app at no extra cost to you.
Related codes
See related trouble codes
Create a free Wrenchify account to unlock the rest for P0670.
Unlock related codesFree forever · No credit card
Frequently asked questions
What does P0670 mean?
P0670 means "Glow Plug Module Control Circuit". It is a generic OBD-II code that points to a fault in the computer & auxiliary output controls.
What are the most common causes of P0670?
glow plug control module faulty; wiring or connector fault — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.
Can I keep driving with this code?
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.
Get the full P0670 diagnosis for your vehicle
Year, make, model + step-by-step repair help — free plan included.