P0671 on Chevrolet
Cylinder 1 Glow Plug Circuit
P0671 on Chevrolet vehicles indicates cylinder 1 glow plug circuit. Au7o has documented this code across 2 Chevrolet models — most commonly on Express, Silverado 3500HD. This is a diesel engine code. Glow plugs are small heating elements that warm each cylinder's combustion chamber so a diesel engine can start easily, especially in cold weather. P0671 means the engine computer (through the glow plug control module) detected an electrical fault in the circuit for the cylinder 1 glow plug — typically an open circuit, a short, or resistance that's out of the expected range. The most noticeable effect is harder cold starting, rough running until warm, or increased white exhaust smoke on startup. Typical repair costs on Chevrolet range from $200 to $1,800, depending on the specific model and root cause.
Common Causes of P0671
- •Failed (open or shorted) cylinder 1 glow plug
- •Damaged or corroded glow plug wiring/connector
- •Loose or corroded glow plug terminal/strap
- •Faulty glow plug relay or control module
- •Broken or chafed harness to the glow plug
- •Poor ground or supply voltage to the glow plug circuit
P0671 on Chevrolet by Model
Chevrolet Express(1 issue)
- 6.6L Duramax LGH Glow Plug and Glow Plug Control Module Failure2011-2016
The 6.6L Duramax LGH offered in Express 2500/3500/4500 vans from 2011 to 2016 has a well-documented glow plug system weakness. Individual glow plugs fail open, and the glow plug control module itself develops open-driver and no-power-to-glow-plug faults - a failure mode common enough that specialist board-repair houses list the 2011-2016 Chevrolet Express 6.6L LGH GPCM as a standing repair line. GM issued a service bulletin covering 2011-2012 Express vans with the LGH and LML Duramax where the malfunction indicator lamp illuminates for glow plug faults; the bulletin notes there is usually no drivability complaint in mild weather, but harder cold starting may be present. In practice owners in cold climates get extended cranking, white startup smoke and a rough first minute of running, plus a persistent MIL that will fail an inspection. Do not confuse this with the 2023+ Express, which uses the completely different 6.6L L5P Duramax and whose injector-related complaints are their own story.
Chevrolet Silverado 3500HD(1 issue)
- Glow Plug Failure and Hard Cold Starting2001-2020
Glow plugs fail causing difficult cold weather starting. Can also swell and break during removal, requiring extraction. Glow plug module can also fail.
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View P0671 across all makes →Frequently Asked Questions
What does P0671 mean on Chevrolet?▼
P0671 stands for "Cylinder 1 Glow Plug Circuit." This is a diesel engine code. Glow plugs are small heating elements that warm each cylinder's combustion chamber so a diesel engine can start easily, especially in cold weather. P0671 means the engine computer (through the glow plug control module) detected an electrical fault in the circuit for the cylinder 1 glow plug — typically an open circuit, a short, or resistance that's out of the expected range. The most noticeable effect is harder cold starting, rough running until warm, or increased white exhaust smoke on startup. On Chevrolet specifically, this code is documented across 2 models.
What causes P0671 on Chevrolet vehicles?▼
Common causes on Chevrolet: Failed (open or shorted) cylinder 1 glow plug, Damaged or corroded glow plug wiring/connector, Loose or corroded glow plug terminal/strap, Faulty glow plug relay or control module, Broken or chafed harness to the glow plug. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0671 on a Chevrolet?▼
Repair costs on Chevrolet range from $200 to $1,800, depending on the specific model and root cause.
Which Chevrolet models have P0671 documented?▼
Au7o has documented P0671 on 2 Chevrolet models: Express, Silverado 3500HD.