Circuit/System Testing

Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B9 ambient air temperature sensor. It may take up to 2 minutes for all vehicle systems to power down.
Test for less than 1 V between the low reference circuit terminal B and ground.
- If 1 V or greater
  repair the short to voltage on the circuit.
- If less than 1 V
Test for less than 10 Ω between the low reference circuit terminal B and ground.
- If 10 Ω or greater
1. Ignition OFF, disconnect the harness connector at the P16 instrument cluster.
2. 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 P16 instrument cluster.
- If less than 10 Ω
Ignition ON.
Verify the scan tool Ambient Air Temperature parameter is greater than 98%.
- If 98% or less
1. Ignition OFF, disconnect the harness connector at the P16 instrument cluster.
2. Test for infinite resistance between the signal circuit and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
  - If infinite resistance, replace the P16 instrument cluster.
- If greater than 98%
Install a 3 A fused jumper wire between the signal circuit terminal A and the low reference circuit terminal B.
Verify the scan tool Ambient Air Temperature parameter is less than 8%.
- If 8% or greater
1. Ignition OFF, disconnect the harness connector at the P16 instrument cluster, ignition ON.
2. Test for less than 1 V between the signal circuit and ground.
  - If 1 V or greater, repair the short to voltage on the circuit.
  - If less than 1 V
3. Ignition OFF
4. 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 P16 instrument cluster.
- If less than 8%
Test or replace the B9 Ambient Air Temperature Sensor.