Circuit/System Testing
WARNING: This page is about a different car, the 2008 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the harness connector of all appropriate sensors for the applicable DTC. Refer to Diagnostic Aids .
- Ignition ON, test for 4.6-5.2 volts between one of the affected 5-volt reference circuits and ground.
- If the voltage is less than the specified range, test for an open between the ECM and the splice for all of the affected components. Or, test for a short to ground on the 5-volt reference circuit for each of the affected components. If all circuits test normal, replace the ECM.
- If the voltage is greater than the specified range, test for a short to voltage on the 5-volt reference circuit for each of the affected components. If all circuits test normal, replace the ECM.
- Connect each component associated with the affected 5-volt reference circuit one at a time while monitoring the appropriate scan tool 5-Volt Reference Circuit Status parameter. The parameter should continue to display OK.
- If the parameter displays Fault when a component is connected, test the signal circuit of that component for a short to voltage. If the circuit tests normal, replace the component.
IMPORTANT:
Additional DTCs will set when disconnecting the components.
IMPORTANT:
A short to voltage on the signal circuit of certain components may cause this DTC to set.