P067E

Code

Generic P — Powertrain

Cylinder 6 Glow Plug Control Circuit Low

Brand: Generic

Type: P — Powertrain

Views: UK: 18 EN: 34 RU: 28

AI status

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Page language: EN

Causes

Failed glow plug at cylinder 6 (open or high resistance)
Broken, corroded, or disconnected connector/wiring to glow plug
Short to ground in the control wiring or connector
Blown fuse or faulty glow relay/heater relay
Faulty glow plug control module, PCM/ECM output driver or internal electronics
Low battery voltage or poor battery connections/ground

Symptoms

Difficult or no cold start on engine start-up (especially in cold weather)
Longer cranking time or repeated cranking
White smoke from exhaust on cold start
Glow plug or preheat indicator lamp may be illuminated or flash
Illuminated MIL/check engine lamp
Possible reduced engine performance or limp mode in some vehicles

What to check

Read DTCs with a scan tool; record freeze-frame and related codes
Check battery voltage and charge state (resting and cranking voltages)
Inspect fuses and glow/heater relay for continuity and proper operation
Visually inspect connectors, wiring and harness routing to cylinder 6 glow plug for damage or corrosion
Check resistance of cylinder 6 glow plug (with battery disconnected)
Measure voltage at the glow plug connector while commanding glow ON with a scan tool

Signal parameters

Expected supply voltage to glow circuit when commanded ON: approx. battery voltage (~11–14.5 V)
Control circuit 'low' condition typically measured near 0–1 V at command output or greatly reduced compared to battery
Typical glow plug resistance: commonly ~0.2–2.0 ohm (varies by design) — a very high or open reading indicates failure
Glow plug current draw when operating: several amps per plug (total bank current often 10–50 A depending on engine and number of plugs)
Cranking voltage should remain above ~9.5–10 V; much lower can cause false low-circuit detections

Diagnostic algorithm

Retrieve and record all codes and freeze-frame data. Note related glow/heater or battery codes.
Verify battery state of charge and charging system. Ensure battery connections and grounds are clean and tight.
Inspect glow plug fuse(s) and relay(s); replace or bench-test relay if suspect.
Visually inspect cylinder 6 glow plug connector and wiring for corrosion, damage, or poor contact; repair as needed.
With ignition off and battery disconnected, measure resistance of the cylinder 6 glow plug between terminal and body/engine ground. Compare to specification or to other cylinders.
Reconnect battery. Using a scan tool, command glow/heater ON and measure voltage at the cylinder 6 connector. Expect near-battery voltage when commanded. If voltage is low, trace back toward relay/module.

Likely causes

Faulty or high-resistance glow plug on cylinder 6
Open or corroded connector at cylinder 6 glow plug
Bad glow plug relay or blown fuse in glow/heater circuit
Damaged wiring harness (short to ground) between module and glow plug
Defective glow plug driver in PCM/ECM or separate glow control module
Low battery/charging system issue causing insufficient supply voltage

Fault status

⚠️ Status

Engine control module detected low voltage on the cylinder 6 glow plug control circuit — possible faulty glow plug, wiring, relay/fuse, or control module.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours