U1153 ACM Loss of CCP Serial Data Communication - HVAC

CIRCUIT DESCRIPTION

DTC U1153 will set if the ignition is ON and the heater and A/C programmer has lost data communication with the CCP.

Diagnosis of this DTC is dependent upon other system symptoms (DTCs) being present with U1153.

TEST CONDITION(S)

^ Ignition in ON.

FAILURE CONDITION(S)

1. Open circuit.

ACTION TAKEN

1. Set DTC U1153

TROUBLESHOOTING HINTS

1. Using a scan tool, attempt to establish communications with CCP.
2. Check CKT 1807 for an open or short to power or ground.
3. Check that CCP is connected to power and ground.
4. DTC CCP U1152 loss of ACM serial data communications may be present with this DTC. If so, this would indicate that both the CCP and ACM were functional when the DTC was set, but they could not communicate with one another.
5. If there are multiple Class 2 DTCs current check for a short to ground or voltage in CKT 1807. Refer to Computer System Diagnosis. Testing and Inspection