P269E

Code

Generic P — Powertrain

Exhaust Aftertreatment Glow Plug Control Circuit High

Brand: Generic

Type: P — Powertrain

Views: UK: 26 EN: 30 RU: 24

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Page language: EN

Causes

Open or damaged wiring in the glow plug control circuit
Short to battery voltage on the control circuit
Corroded or loose connector at glow plug(s) or control module
Failed glow plug relay or dedicated glow plug driver/module
Failed glow plug(s) (internal short or open)
Blown or poor fuse/power supply to glow plug circuit

Symptoms

Malfunction Indicator Lamp (MIL) or engine light illuminated
Aftertreatment/DPF heating not operating or delayed
DPF regeneration failures or storage of DPF-related faults
Reduced performance or limp mode on some vehicles
Cold-start or warm-up problems in systems that rely on aftertreatment glow plugs
Diagnostic trouble code P269E stored in ECU memory

What to check

Read and record freeze frame and related DTCs with a scan tool; attempt to reproduce the fault
Visual inspection of glow plug wiring, connectors, and harness for damage, heat exposure, corrosion
Check relevant fuses and relay(s) for proper operation
Backprobe the glow plug control connector and monitor voltage while commanding the circuit ON/OFF with a scan tool
Measure supply voltage at fuse/relay and at the glow plug/module power pins (battery voltage expected ~11–14.5 V)
Measure resistance of individual glow plugs (with battery disconnected) and check for open/short

Signal parameters

Battery supply voltage: ~11–14.5 V (engine off/ON as appropriate)
Expected control output (generic low-side driver): ON = low voltage close to ground (
High-condition threshold (generic): control circuit voltage higher than expected when commanded ON (example >2–3 V) may trigger code; consult OEM spec for exact threshold
Glow plug resistance (typical range): ~0.1–5 Ω per plug depending on design (measure with battery disconnected)
Typical current draw: several amps per glow plug; total depends on number of plugs and driver design (use clamp meter while commanding ON)

Diagnostic algorithm

Verify and record P269E and any related DTCs. Note freeze frame and vehicle conditions when the code set (temperature, engine speed, battery voltage).
Visually inspect wiring, connectors, and harness routing for chafing, heat damage, corrosion, or loose pins at glow plugs, relay/driver module and ECM.
Check fuses and relay(s) supplying the glow plug circuit. Replace suspect fuses/relays and retest.
With vehicle key ON (engine off) use a scan tool to command the aftertreatment glow plug circuit ON and monitor the control circuit voltage at the driver module and at individual glow plug connectors. Expect switching behavior; compare to OEM spec.
If commanded ON, measure voltage on the control output. If voltage remains high (above specified ON threshold) suspect open low-side or short to battery. If voltage is low when OFF, suspect short to ground or driver stuck ON.
With battery disconnected, measure resistance of each glow plug to ground. Replace any glow plug that is open or outside specified resistance range.
Check continuity between ECM/driver connector and glow plug module/control harness. Repair any opens or high-resistance joints. Check for shorts to battery (+) and to ground.
If wiring and glow plugs check OK, bench-test or substitute the glow plug driver/relay module (if removable) and retest circuit behavior.
If replacement of wiring, connectors, fuses, and driver does not clear the issue, test or substitute the ECM/PCM or consult OEM procedures — ECM faults are less common but possible.
After repairs, clear codes, perform a functional test (command ON/OFF), perform DPF regeneration where applicable, and road-test to confirm code does not return.

Likely causes

Corroded/loose connector or damaged wiring between ECM and glow plug module
Failed glow plug relay or driver module
Open or shorted glow plug(s) or harness caused by heat/abrasion
Blown fuse or loss of supply/ground to the driver
Less likely: ECM/PCM internal driver fault

Fault status

⚠️ Status

Exhaust Aftertreatment Glow Plug Control Circuit High — control circuit voltage higher than allowed threshold detected on the aftertreatment glow plug circuit. May prevent proper heating of the aftertreatment system; inspect wiring, connectors, fuses, relay/driver and glow plugs.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-3.0 hours