Pinpoint Test I : The Defrost System Does Not Shut Off Automatically - DATC (Dual Automatic Temperature Control)
- I1 CHECK FOR BCM (BODY CONTROL MODULE) DIAGNOSTIC TROUBLE CODES (DTCS)
- Ignition ON.
- Using a scan tool, perform BCM self-test.
Are any BCM Diagnostic Trouble Codes (DTCs) present?
Yes For DTC B1C84:11 or B1C84:14, GO to I3For all other Diagnostic Trouble Codes (DTCs), REFER to: Body Control Module (BCM) . No GO to I2 - I2 CHECK FOR A SHORT TO VOLTAGE IN THE DEFROST GRID CIRCUIT
- Ignition OFF.
- Disconnect: Rear Window Defrost Relay.
- Ignition ON.
- Measure:
Positive Lead Measurement / Action Negative Lead
Rear Window Defrost Relay, socket pin 5Ground
Is any voltage present?
Yes REPAIR the circuit. No INSTALL a new rear window defrost relay. - I3 CHECK FOR A SHORT TO GROUND IN THE REAR WINDOW DEFROST RELAY CONTROL CIRCUIT WITH THE BCM (BODY CONTROL MODULE) DISCONNECTED
- Ignition OFF.
- Disconnect: Rear Window Defrost Relay.
- Disconnect: BCM C2280C .
- Measure:
Positive Lead Measurement / Action Negative Lead
Rear Window Defrost Relay, socket pin 2Ground
Is the resistance greater than 10, 000 ohms?
Yes GO to I4 No REPAIR the circuit. - I4 CHECK FOR CORRECT BCM (BODY CONTROL MODULE) OPERATION
- Ignition OFF.
- Disconnect and inspect all the BCM connectors.
- Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins as necessary
- pushed-out pins - install new pins as necessary
- Reconnect the BCM connectors and all previously disconnected rear window defrost system connectors. Make sure they seat and latch correctly.
- Operate the system and determine if the concern is still present.
Is the concern still present?
Yes CHECK OASIS for any applicable Technical Service Bulletins (TSBs). If a TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, INSTALL a new BCM. No The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.