P06E3

Code

Generic P — Powertrain

Cylinder 12 Glow Plug Control Circuit High

Brand: Generic

Type: P — Powertrain

Views: UK: 24 EN: 39 RU: 25

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Read and record freeze frame and live data for glow plug/driver PIDs with a scan tool
Visually inspect wiring harness and connectors at cylinder 12, glow plugs, and glow control module for damage or corrosion
Check for Diagnostic Trouble Codes (other glow plug or electrical codes) and note any patterns
Measure voltage at the glow plug connector with ignition/engine in the glow/activation state and when off
Measure resistance of the suspect glow plug (engine cold, glow plug removed) and compare to specification
Perform a current draw test on the glow plug/driver channel when activated to verify expected current

Expected glow plug element resistance (typical): ~0.2–2.0 ohm (varies by manufacturer)
Voltage at glow plug terminal when activated: approximately battery voltage (9–14 V) for direct-feed systems, or pulsed/PWM in controlled systems
Voltage at control/driver output when off: near 0 V or open-circuit (depends on driver topology)
Current draw per glow plug when activated: commonly several amps (2–15 A depending on design)
A 'high' fault means the control circuit voltage or signal is higher than the module/ECM expects (possible short to B+ or driver fault)

Record freeze frame and live data. Note if the fault is current or voltage related and whether it is present continuously or intermittently.
Visually inspect the harness, connector and pins at cylinder 12 glow plug and glow control module for damage, corrosion, melted insulation or loose terminals. Repair as needed.
With ignition off and battery disconnected if required by manufacturer safety procedures, measure resistance of the suspect glow plug (remove plug). Compare to specification; replace if out of range.
Reconnect battery. With a scan tool, command the glow function ON and measure voltage at the glow plug connector and at the control module output. Verify expected behavior (steady battery voltage, or proper PWM).
Perform a current draw test on the channel while commanded ON. Excessive or zero current indicates short or open respectively.
If voltage at the connector is high when it should be low (or vice versa), trace wiring for short to B+ or open circuit. Repair/replace damaged wiring or connectors.
If wiring and glow plug check good, test/replace the glow plug driver/module per manufacturer procedure. Re-test after replacement.
If fault persists after replacing module and verifying wiring and glow plug, consider ECM/PCM fault and consult manufacturer guidance before replacement.
Clear codes and perform several cold-start cycles or a road test to confirm repair.

Connector corrosion or water ingress at cylinder 12 glow plug connector
Wiring rubbed through and shorted to power or another circuit
Glow plug driver inside the glow control module has failed and is applying unexpected voltage
Individual glow plug has internal short or abnormal resistance