Powertrain
generic / SAE
P2688
Fuel Supply Heater Control Circuit Low
Voltage on the fuel supply heater control line is below the expected window. The sensor heater warms the element to operating temperature (~600 °C); without it the lambda sensor stays inactive in closed loop and the ECM cannot trim mixture.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number6 / 88
Possible causes
- Control wire shorted to ground high
- Relay coil short medium
- Connector pins corroded - high contact resistance low
Inspection / repair
- Difficulty: medium
- DIY: possible
- Estimated cost: 80–400 €
- Estimated time: 0.5–2 h
- Component: fuel supply heater
- Component: wiring harness
- MIL / check engine light
Sources
References
sae:J2012