Trouble codes › By vehicle › GMC Yukon

Common check-engine codes on the GMC Yukon

2007-2023

The Yukon shares GM's truck V8s with the Tahoe, Suburban, Silverado and Sierra, and the same common codes: AFM/DFM lifter misfires, oil pressure sensor faults, EVAP and throttle codes.

Most common: P0300, P0521, P0171, P0449, P2135, P0420.

Known problems on the GMC Yukon

P0300 Random/Multiple Cylinder Misfire Detected

P0300 means the engine is misfiring in more than one cylinder, often from worn plugs or coils, a vacuum leak or low fuel pressure.

On the GMC Yukon: Misfires with ticking on Active or Dynamic Fuel Management V8s can be a collapsed lifter. Rule out plugs and coils first.

P0300: causes, can I keep driving, and what to check first →

P0521 Engine Oil Pressure Sensor/Switch "A" Range/Performance

P0521 means the oil pressure reading doesn't make sense for how the engine is running; check the oil level and have real pressure tested.

On the GMC Yukon: Oil pressure sensor or clogged screen giving a false reading; confirm real pressure with a gauge.

P0521: causes, can I keep driving, and what to check first →

P0171 System Too Lean (Bank 1)

P0171 means bank 1 is running lean (too much air or too little fuel), most often from a vacuum leak or a dirty MAF sensor.

On the GMC Yukon: Lean codes, often with P0174: intake gaskets, MAF sensor or vacuum leaks.

P0171: causes, can I keep driving, and what to check first →

P0449 Evaporative Emission System Vent Valve/Solenoid Circuit

P0449 means there's an electrical fault in the EVAP vent valve circuit.

On the GMC Yukon: EVAP vent solenoid near the tank sticking.

P0449: causes, can I keep driving, and what to check first →

P2135 Throttle/Pedal Position Sensor/Switch "A"/"B" Voltage Correlation

P2135 means the two throttle position sensors disagree, so the engine computer limits power; usually a failing throttle body.

On the GMC Yukon: Throttle position correlation: failing throttle body or connector.

P2135: causes, can I keep driving, and what to check first →

P0420 Catalyst System Efficiency Below Threshold (Bank 1)

P0420 means the catalytic converter on bank 1 isn't cleaning the exhaust well enough, usually a worn converter, an exhaust leak or a lazy oxygen sensor.

On the GMC Yukon: Catalyst efficiency at higher mileage.

P0420: causes, can I keep driving, and what to check first →

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Common codes and known problems as widely reported for these model years; your vehicle may differ. Check nhtsa.gov/recalls and ask a dealer about service bulletins for your VIN, and confirm in your service information.