P0675
Cylinder 5 Glow Plug Circuit
If your code reader dashboard displays the generic DTC error code P0675, your vehicle is currently experiencing an active failure related to "Cylinder 5 Glow Plug Circuit". Proper system troubleshooting is required to safely clear this warning.
Driver's Summary
Code P0675 means your vehicle detected a problem with the cylinder 5 glow plug circuit system. Drivers typically experience engine struggles to start in freezing temps, check engine light when this code is active. You can continue normal driving, but schedule an inspection at your next service appointment to clear this code properly.
Symptoms
Engine struggles to start in freezing temps, check engine light
Common Causes
- Bad cylinder 5 glow plug
- Open circuit in the harness
- Corroded glow plug bus bar
- Glow plug module fault
How to Fix
- 1 Test and replace cylinder 5 glow plug
- 2 Repair open wiring
- 3 Clean or replace bus bar
- 4 Replace glow plug control unit
Technical Explanation
Detection of P0675 occurs when the ECM cross-references multiple sensor inputs and determines that the reported values are physically inconsistent or out-of-range. A two-trip detection strategy is employed for most powertrain codes: the fault must be detected on one drive cycle, the vehicle key-cycled off, and the fault detected again on the next drive cycle before the MIL illuminates and a permanent DTC is stored. The MIL illuminates after the fault is confirmed on two consecutive drive cycles, and the freeze frame data captured at first detection is stored in the PCM's memory for diagnostic reference.
Is It Safe to Drive?
Code P0675 has minimal impact on immediate driving safety. However, the underlying bad cylinder 5 glow plug issue will cause this vehicle to fail an emissions inspection and may gradually affect fuel economy if left unrepaired.
Mechanic's Pro Tip
Module replacement should always be the last resort for P0675 after exhaustively verifying all power supply circuits, ground connections, and communication bus wiring. Use a wiring diagram to locate all fuses, relays, and ground points for the affected module, and measure voltage drop on each ground with the circuit loaded. A module "failure" is frequently a corroded ground eyelet or a weak battery causing brownout conditions — fix these first and you'll save hundreds of dollars on an unnecessary module replacement.
Glow plug replacement: $80 - $250