P067E
6 Glow Plug Control Circuit LowP067E is a generic OBD-II powertrain diagnostic trouble code: 6 Glow Plug Control Circuit Low. It is logged by the engine control unit when the glow monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.
What P067E means
DTC P067E — Glow Plug Module Cylinder 6 Control Circuit Low — is a SAE generic powertrain code applicable to diesel engines. It is stored by the ECM or a dedicated glow plug control module (GPCM) when the control circuit for the cylinder 6 glow plug reports an abnormally low voltage signal — a condition indicating a short circuit to ground, an open circuit drawing no current, or a failed glow plug drawing excess current that collapses the circuit voltage below the expected operating window.
Glow plugs are critical for cold starting and afterglow (post-start emissions warm-up) in diesel engines. Each glow plug is individually controlled and monitored; when the GPCM commands cylinder 6's plug on and observes a voltage reading below its low threshold, it logs P067E. The most frequent causes are a failed (internally shorted or open-circuit) glow plug in cylinder 6, corroded or damaged wiring between the GPCM and the plug, a faulty GPCM output driver for that channel, or a poor glow plug earth return path.
While P067E does not disable the engine once warm, it can cause difficult cold starting, rough idle immediately after a cold start, increased exhaust smoke during warm-up, and may trigger a cold-start inhibit on some vehicles. The fault is particularly noticeable at ambient temperatures below 5 °C. Because diesel combustion relies on compression heat plus glow-plug pre-warming, a disabled cylinder 6 plug degrades cold-start combustion quality and increases short-term emissions.
Common causes
Most-frequently reported root causes when P067E is logged.
-
1
Failed glow plug in cylinder 6 — internally shorted, causing low-side voltage collapse (most common)
-
2
Open-circuit glow plug in cylinder 6 — wiring or plug element break causing zero current flow
-
3
Corroded or damaged wiring/connector between GPCM and cylinder 6 glow plug
-
4
Poor or broken glow plug earth/ground return at the cylinder head or harness splice
-
5
Failed GPCM output channel for cylinder 6 (GPCM internal fault)
-
6
Glow plug relay or bus-bar corrosion reducing voltage to the glow plug rail
-
7
Incorrect glow plug part installed with incompatible resistance specification
Symptoms drivers notice
How to diagnose P067E
A typical diagnostic flow when this code is present.
-
1
Confirm the fault with a scan tool; check for co-stored codes on other cylinders that may indicate a systemic GPCM or wiring issue rather than a single plug failure
-
2
Measure glow plug resistance at the plug connector — a serviceable diesel glow plug typically reads 0.5–2.0 Ω cold; values near 0 Ω indicate a short, OL indicates open circuit
-
3
Inspect the wiring harness and connector at the cylinder 6 glow plug for corrosion, heat damage, or chafed insulation
-
4
Check the glow plug earth/ground path — measure resistance from plug body to chassis ground (should be less than 0.5 Ω)
-
5
With harness disconnected from the plug, command the GPCM to activate cylinder 6 circuit and measure output voltage at the harness side — low or absent voltage points to GPCM or wiring fault
-
6
Replace the glow plug in cylinder 6 if resistance is out of specification, then clear the code and perform a cold-start verification test
Vehicles where we've handled P067E
Platforms in our catalogue with confirmed P067E coverage.
Related powertrain codes
Frequently asked questions
Can I drive with P067E active?
Yes, with caution. The engine will run normally once warm. However, cold starting will be impaired — particularly at low ambient temperatures — and fuel consumption and emissions during warm-up will increase. Repair promptly to avoid cold-start damage and to remain emissions-compliant.
Should I replace all glow plugs or just cylinder 6?
If the vehicle has high mileage and the plugs have never been changed, replacing the full set while cylinder 6 is being addressed is advisable. Glow plugs typically fail in clusters as they age together. Replacing only cylinder 6 risks another code appearing on a neighbouring cylinder shortly after.
What is the GPCM and where is it located?
The Glow Plug Control Module (GPCM) is a dedicated controller that manages glow plug activation timing, duration, and current monitoring for each cylinder independently. It is typically mounted on or near the valve cover or in the engine bay fuse/relay box, depending on the vehicle. It receives commands from the ECM and reports faults back to it.
P067E appeared after an engine rebuild — what should I check first?
After an engine rebuild, verify that the original (or new) cylinder 6 glow plug was correctly torqued to specification and its harness connector was fully seated. Also confirm the plug earth path (through the cylinder head to chassis) is intact — a reused head gasket or cleaned head surface may have introduced a ground continuity issue.
Disabling P067E in software
RaceTune can permanently disable P067E — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.
ECUs with a P067E disable in our catalogue
Confirmed coverage from our recipe database — we support many more families. Upload your file and our identifier will match it automatically.
- Bosch EDC17CP57 verified 2 software versions
- Bosch EDC17C56 verified 1 software version
- Bosch EDC17C66 verified 1 software version
- Bosch MD1CP002 verified 1 software version
- Bosch MD1CP004 verified 1 software version
- Bosch MD1CS001 verified 1 software version
Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.
Got P067E in your scan?
Upload your ECU file — we'll identify the exact software version and confirm whether a disable is available for your car.
Upload your file