OBD-II Code
P0676
Severity
Not yet reviewed
Nobody on our side has assessed this code yet, so we are not going to guess at how serious it is.
Can you drive it
We cannot say
Treat it as unknown until a shop reads it with live data. If the check-engine light is FLASHING, stop driving as soon as it is safe to — that means an active misfire, whatever the code.
Indicative cost (USD)
$80–$3,200
From this code's diagnostic notes. Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.
$80 (single plug, accessible) to $3,200 (seized-plug extraction with head removal on the 6.0).
P0676 means the ECU detected a glow plug circuit fault on cylinder 5 — open, short, or out-of-spec resistance flagged by the GPCM per-cylinder monitor.
How a shop works this
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.
Note every code that is set, not just this one.
Codes that appear together usually narrow the cause faster than any one of them read alone.
Read the freeze frame — the conditions the fault was recorded under.
Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.
Confirm the fault is current rather than history.
Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.
Then follow the diagnostic notes further down this page, in the order they are written.
They are written in the order a shop works this code, cheapest checks first. Where they name a component, inspect its wiring and connector before replacing it.
If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.
Common symptoms
- Check engine light
Read the full diagnostic procedureP0676 means the ECU detected a glow plug circuit fault on cylinder 5 — open, short, or out-of-spec resistance flagged by the GPCM per-cylinder monito…
P0676 means the ECU detected a glow plug circuit fault on cylinder 5 — open, short, or out-of-spec resistance flagged by the GPCM per-cylinder monitor.
The cheapest-first diagnostic ladder
- Ohm cylinder 5's plug at its terminal — healthy 0.4-2.0 ohms cold (0.6-1.2 typical), 0 shorted, infinite open, 4+ weak.
- Confirm GPCM PWM command at 0-100% duty cycle with glow-on time 5-30 sec scaled to coolant temp.
- Clamp an amp probe on the cyl 5 feed and verify 7-20A initial inrush falling to 5-15A as the plug heats — 0A is open, sustained 20A+ is short. Cylinder 5 only exists on 5-cylinder, 6-cylinder, 8-cylinder, or 10-cylinder diesels — typically inline-6 (Cummins, OM606), V6 (OM642 Sprinter), V8 (Powerstroke, Duramax), or V10 (Touareg TDI). Test resistance INDIVIDUALLY at the glow plug terminal — pulling a shorted plug measures 0 ohms; an open plug measures infinite; a marginally weak plug measures 4+ ohms cold and is the most common cold-start hard-start root cause. Replace as a set on diesel engines — mixed-age plugs cause progressive failure.
Vehicle-specific patterns2003-2007 Ford 6.0L Powerstroke V8 throws P0676 from cylinder 5 (driver's bank, third from front) — cyl 5 sits directly under the EGR cooler on the 6…
- 2003-2007Ford 6.0L Powerstroke V8 throws P0676 from cylinder 5 (driver's bank, third from front) — cyl 5 sits directly under the EGR cooler on the 6.0 and is the cylinder most likely to seize a glow plug into the head due to coolant seepage from cracked EGR cooler internals; if the plug won't budge, soak for 48 hr and use a torque-limited extractor.
- 2008-2010Ford 6.4L Powerstroke commonly throws P0676 from the under-valve-cover harness rubbing through at the rocker shaft.
- 2001-2016Duramax V8 throws P0676 on cylinder 5 (driver's bank) — the LB7 and LLY are especially prone because their factory plugs were a known weak design.
- 2007-2018Cummins 6.7 inline-6 commonly throws P0676 on the rear-of-block cylinders (5 and 6) where the firewall traps heat.
- 2007-2018Mercedes Sprinter OM642 V6 BlueTec uses cyl 5 on the rear bank — the V6 layout means cyl 5 is harder to access than cyl 1-4.
Estimated repair$80 (single plug, accessible) to $3,200 (seized-plug extraction with head removal on the 6.0).
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