KM57 - Check ACD Circuit Continuity From LP Switch to PCM

- Key "OFF".

- Low Pressure (LP) switch disconnected.

- Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.

- Install breakout box, leave PCM disconnected.

- Measure resistance between test pin 10 at the breakout box and PCM side of LP switch vehicle harness connector.

- Is resistance less than 5.0 ohms?

Yes -- Replace PCM. Remove breakout box. Reconnect all components. Re-evaluate symptom.

No -- Service open circuit. Reconnect all components. Re-evaluate symptom.