Pinpoint Test B: The Defrost System Does Not Shut Off Automatically

B1 CHECK FOR BODY CONTROL MODULE (BCM) 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 B112D:15, GO to B2
  For DTC B1C84:11, GO to B5
  
  For all other Diagnostic Trouble Codes (DTCs), DTC Chart:
  
  REFER to: BODY CONTROL MODULE (BCM) .
- No : GO to B3

B2 CHECK FOR A SHORT TO VOLTAGE IN THE DEFROST SWITCH LIGHT-EMITTING DIODE (LED) CIRCUIT

Ignition OFF.
Disconnect: Defrost Switch C241.
Disconnect: Ignition Relay.
Disconnect: BCM C2280C.

Connect a fused jumper wire:

Positive Lead	Measurement/Action	Negative Lead
Ignition Relay, socket pin 3, circuit SDC02 (RD)		Ignition Relay, socket pin 5, circuit DC21 (GY/BN)

Measure:

Positive Lead	Measurement/Action	Negative Lead
C241-9		Ground

Is any voltage present?

Yes : REMOVE the fused jumper wire. REPAIR the circuit.
No : REMOVE the fused jumper wire. GO to B6

B3 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 5, circuit CRD06 (BN/YE)		Ground

Is any voltage present?

Yes : REPAIR the circuit.
No : GO to B4

B4 CHECK FOR A SHORT TO GROUND IN THE REAR WINDOW DEFROST RELAY CONTROL CIRCUIT

NOTE: The following step uses a test light to simulate normal circuit loads. Use only the test light recommended . To avoid connector terminal damage, use the Flex Probe Kit for the test light probe connection to the vehicle. Do not use the test light probe directly on any connector.

Measure:

Positive Lead	Measurement/Action	Negative Lead
Rear Window Defrost Relay, socket pin 1, circuit SBP10 (YE/RD)		Rear Window Defrost Relay, socket pin 2, circuit CRD02 (BN/BU)

Does the test light illuminate?

Yes : GO to B5
No : INSTALL a new rear window defrost relay.

B5 CHECK FOR A SHORT TO GROUND IN THE REAR WINDOW DEFROST RELAY CONTROL CIRCUIT WITH THE BODY CONTROL MODULE (BCM) DISCONNECTED

Ignition OFF.
Disconnect: Rear Window Defrost Relay (if not previously disconnected).
Disconnect: BCM C2280C.

Measure:

Positive Lead	Measurement/Action	Negative Lead
Rear Window Defrost Relay, socket pin 2, circuit CRD02 (BN/BU)		Ground

Is the resistance greater than 10, 000 ohms?

Yes : GO to B6
No : REPAIR the circuit.

B6 CHECK FOR CORRECT BODY CONTROL MODULE (BCM) OPERATION
- Ignition OFF.
- Connect: Ignition Relay (if previously disconnected).
- 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 .
  REFER to: BODY CONTROL MODULE (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.