Circuit/System Testing
WARNING: This page is about a different car, the 2017 Cadillac ATS. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition/Vehicle & All vehicle systems Off
- Disconnect the electrical connector: B9 Ambient Air Temperature Sensor
- Test for less than 10 Ω between the test points: Low Reference circuit terminal B or 2 & Ground
- If 10 Ω or greater
- Disconnect the electrical connector: P16 Instrument Cluster
- Test for less than 2 Ω between the test points: Low Reference circuit terminal B or 2 @ Component harness & the other end of the circuit
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the component: P16 Instrument Cluster
- If less than 10 Ω
- Ignition On/Vehicle In Service Mode
- Verify the scan tool parameter: Ambient Air Temperature = If 98% or greater
- If less than 98%
- Ignition/Vehicle Off
- Disconnect the electrical connector: P16 Instrument Cluster
- Test for infinite resistance between the test points: Signal circuit terminal A or 1 @ Component harness & Ground
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance, replace the component: P16 Instrument Cluster
- If 98% or greater
- Connect a 3 A fused jumper wire between the test points: Signal circuit terminal A or 1 & Low Reference circuit terminal B or 2
- Verify the scan tool parameter: Ambient Air Temperature = Less than 8%
- If 8% or greater
- Ignition/Vehicle Off & Remove Jumper wire(s)
- Disconnect the electrical connector: P16 Instrument Cluster
- Ignition On/Vehicle In Service Mode
- Test for less than 1 V between the test points: Signal circuit @ Component harness & Ground
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V
- Ignition/Vehicle Off
- Test for less than 2 Ω between the test points: Signal circuit @ Component harness & the other end of the circuit
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the component: P16 Instrument Cluster
- If less than 8%
- Test or replace the component: B9 Ambient Air Temperature Sensor
NOTE:
It may take up to 2 min for all vehicle systems to power down before an accurate ground or low reference circuit continuity test can be performed.