Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Test Description
The numbers below refer to the step numbers on the diagnostic procedures.
- 2
DTC P0412 AIR Solenoid Valve Control Circuit and P0418 AIR Pump Relay Control Circuit should be diagnosed first if either are set. - 3
Begins testing for a short to ground in the AIR pump feed circuit. - 4
Listen for a running motor. Command both the ON and OFF states. Repeat the commands as necessary. - 5
Begins testing for a short to voltage in the pump feed circuit. - 6
Tests for voltage at the AIR pump relay switch feed circuit. - 7
Bypasses the relay. - 8
Tests for voltage on the AIR pump feed circuit. - 9
Tests for an open on the pump ground circuit. - 28
The AIR Pump is not designed to run continuously. If the pump needs to be replaced, check for conditions that may cause continuous pump operation.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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