Circuit/System Testing
WARNING: This page is about a different car, the 2015 Buick Encore. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B1 A/C Refrigerant Pressure Sensor. It may take up to 2 min for all vehicle systems to power down.
- Test for less than 10 Ω between the low reference circuit terminal 1 and ground.
- If 10 Ω or greater
- Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
- Test for less than 2 Ω in the low reference circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the K20 Engine Control Module.
- If less than 10 Ω
- Ignition ON.
- Test for 4.8-5.2 V between the 5 V reference circuit terminal 2 and ground.
- If less than 4.8 V
- Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
- Test for infinite resistance between the 5 V reference circuit and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance
- Test for less than 2 Ω in the 5 V reference circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the K20 Engine Control Module.
- If greater than 5.2 V
- Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON.
- Test for less than 1 V between the 5 V reference circuit and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K20 Engine Control Module.
- If between 4.8-5.2 V
- Verify the scan tool A/C High Side Pressure Sensor parameter is less than .25 V.
- If .25 V or greater
- Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON.
- Test for less than 1 V between the signal circuit terminal 3 and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K20 Engine Control Module.
- If less than .25 V
- Install a 3 A fused jumper wire between the signal circuit terminal 3 and the 5 V reference circuit terminal 2.
- Verify the scan tool A/C High Side Pressure Sensor parameter is greater than 4.8 V.
- If 4.8 V or less
- Ignition OFF, remove the jumper wire, disconnect the harness connector at the K20 Engine Control Module.
- Test for infinite resistance between the signal circuit terminal 3 and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance
- Test for less than 2 Ω in the signal circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the K20 Engine Control Module.
- If greater than 4.8 V
- Test or replace the B1 A/C Refrigerant Pressure Sensor.