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

B1 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?
1. Yes : For DTC B112D:15, GO to B2
  For DTC B1C84:11 or B1C84:14, GO to B5
  
  For all other Diagnostic Trouble Codes (DTCs),
  
  REFER to: BODY CONTROL MODULE (BCM) .
2. No : GO to B3

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

Ignition OFF.
Disconnect: PAD Indicator/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 CDC21 (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. INSTALL a new PAD Indicator/Defrost Switch.
REFER to: PASSENGER AIRBAG DEACTIVATION (PAD) INDICATOR .

RETEST the system. If the concern is still present, 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 in the Special Tools table at the beginning of this service information. 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 SBB23 (WH/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 BCM (BODY CONTROL MODULE) 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 BCM (BODY CONTROL MODULE) 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?
1. 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) .
2. 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.