P0682

Cylinder 12 Glow Plug Circuit/Open

Severity

⚠️ Medium

Can you drive?

Yes, but get it checked soon

Approx. repair cost

$33–89 (est.)

Symptoms

Difficulty starting a large diesel engine in cold weather
Check Engine Light
White smoke on startup
Unstable engine operation after starting
Glow plug indicator

Causes

Burnt out glow plug cylinder 12
Broken power wire
Connector damage
GPCM module malfunction
Oxidation of contacts

How to Fix

Read OBD-II codes
Measure the resistance of the glow plug of cylinder 12 (standard: 0.5–2 Ohm)
Inspect the wiring and connector
Check supply voltage
Replace a faulty glow plug
If the error occurs again - GPCM diagnostics

Related codes

P0681 P0680 P0670