Pinpoint Test A: The Defrost System Is Inoperative

A1 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 B1013:11 or B1013:23, GO to A16
  For DTC B112D:11, GO to A4
  
  For DTC B112D:15, GO to A5
  
  For DTC B1C84:12, GO to A18
  
  For DTC B1C84:13, GO to A8
  
  For all other Diagnostic Trouble Codes (DTCs), REFER to: BODY CONTROL MODULE (BCM) .
- No : GO to A2

A2 CHECK THE REAR WINDOW DEFROST GRID VOLTAGE

Ignition OFF.
Disconnect: Rear Window Defrost Grid C402A.
Ignition ON.
Activate the rear window defrost switch.

Measure:

Positive Lead	Measurement/Action	Negative Lead
C402A-1		Ground

Is the voltage greater than 11 volts?

Yes : GO to A3
No : GO to A8

A3 CHECK THE REAR WINDOW DEFROST GRID GROUND

Ignition OFF.
Disconnect: Rear Window Defrost Grid C402B.

Measure:

Positive Lead	Measurement/Action	Negative Lead
C402B-1		Ground

Is the resistance less than 3 ohms?

Yes : CARRY OUT the Grid Wire Test. REFER to GRID WIRE TEST . REPAIR the rear window defrost grid or INSTALL a new rear window glass.
REFER to: HEATED WINDOW GRID WIRE REPAIR .

or REFER to: REAR WINDOW GLASS - 5-DOOR .
No : REPAIR the circuit.

A4 CHECK THE REAR WINDOW DEFROST LIGHT-EMITTING DIODE (LED) CIRCUIT FOR A SHORT TO GROUND

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

Measure:

Positive Lead	Measurement/Action	Negative Lead
C241-9		Ground

Is the resistance greater than 10, 000 ohms?

Yes : GO to A19
No : REPAIR the circuit.

A5 CHECK THE REAR WINDOW DEFROST LIGHT-EMITTING DIODE (LED) CIRCUIT OPERATION

Ignition OFF.
Disconnect: BCM C2280C.

Connect a fused jumper wire:

Positive Lead	Measurement/Action	Negative Lead
Positive Battery Terminal		C2280C-2

Is the rear window defrost switch LED illuminated?

Yes : REMOVE the fused jumper wire. GO to A19
No : REMOVE the fused jumper wire. GO to A6

A6 CHECK THE REAR WINDOW DEFROST LIGHT-EMITTING DIODE (LED) CIRCUIT FOR AN OPEN

Disconnect: Defrost Switch C241.

Measure:

Positive Lead	Measurement/Action	Negative Lead
C241-9		C2280C-2

Is the resistance less than 3 ohms?

Yes : GO to A7
No : REPAIR the circuit.

A7 CHECK THE REAR WINDOW DEFROST SWITCH GROUND CIRCUIT FOR AN OPEN

Measure:

Positive Lead	Measurement/Action	Negative Lead
C241-12		Ground

Is the resistance less than 3 ohms?

Yes : INSTALL a new rear window defrost switch.
No : REPAIR the circuit.

A8 CHECK THE VOLTAGE TO THE REAR WINDOW DEFROST RELAY

Ignition OFF.
Disconnect: Rear Window Defrost Relay.
Ignition ON.

Measure:

Positive Lead	Measurement/Action	Negative Lead
Rear Window Defrost Relay, socket pin 1, circuit SBP10 (YE/RD)		Ground
Rear Window Defrost Relay, socket pin 3, circuit SBP10 (YE/RD)		Ground

Are the voltages greater than 11 volts?

Yes : GO to A9
No : VERIFY the RJB fuse 10 (25A) is OK. If OK, REPAIR the circuit. If not OK, REFER to the SYSTEM WIRING DIAGRAMS to identify the possible causes of the circuit short.

A9 CHECK THE BODY CONTROL MODULE (BCM) OUTPUT

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.

Ignition ON.
Activate the rear window defrost switch.

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 : If DTC B1C84:13 is present, INSTALL a new rear window defrost relay.
If DTC B1C84:13 is not present, GO to A10
No : If DTC B1C84:13 is present, GO to A12
If DTC B1C84:13 is not present, GO to A11

A10 CHECK THE REAR WINDOW DEFROST RELAY
- Ignition OFF.
- Carry out the REAR WINDOW DEFROST RELAY COMPONENT TEST .
  Refer to OEM WIRING DIAGRAMS COMPONENT TESTING -- ELECTRIC for schematic and connector information.
Did the rear window defrost relay pass the component test?
- Yes : REPAIR circuit CRD06 (BN/YE) for an open.
- No : INSTALL a new rear window defrost relay.
A11 CHECK THE REAR DEFROST SWITCH (R_DEFRST_SW) PARAMETER IDENTIFICATION (PID)
- Ignition ON.
- Using a scan tool, view BCM Parameter Identifications (PIDs).
- Monitor the BCM Parameter Identification (PID) R_DEFRST_SW while pressing and releasing the rear window defrost switch.
Does the Parameter Identification (PID) status change when the rear window defrost switch is pressed and released?
- Yes : GO to A12
- No : GO to A13

A12 CHECK THE REAR WINDOW DEFROST RELAY CONTROL CIRCUIT FOR AN OPEN

Ignition OFF.
Disconnect: BCM C2280B.

Measure:

Positive Lead	Measurement/Action	Negative Lead
Rear Window Defrost Relay, socket pin 2, circuit CRD02 (BN/BU)		C2280B-22

Is the resistance less than 3 ohms?

Yes : GO to A19
No : REPAIR the circuit.

A13 CHECK THE BODY CONTROL MODULE (BCM) DEFROST SWITCH INPUT

Ignition OFF.
Disconnect: BCM C2280C.
Activate the rear window defrost switch while observing the test light.

Measure:

Positive Lead	Measurement/Action	Negative Lead
Positive Battery Terminal		C2280C-45

Does the test light illuminate when the rear window defrost switch is pressed?

Yes : GO to A19
No : GO to A14

A14 CHECK THE REAR WINDOW DEFROST SWITCH GROUND CIRCUIT FOR AN OPEN

Disconnect: Defrost Switch C241.

Measure:

Positive Lead	Measurement/Action	Negative Lead
C241-12		Ground

Is the resistance less than 3 ohms?

Yes : GO to A15
No : REPAIR the circuit.

A15 CHECK THE REAR WINDOW DEFROST SWITCH CIRCUIT FOR AN OPEN

Measure:

Positive Lead	Measurement/Action	Negative Lead
C241-1		C2280C-45

Is the resistance less than 3 ohms?

Yes : INSTALL a new rear window defrost switch.
No : REPAIR the circuit.

A16 CHECK THE REAR WINDOW DEFROST SWITCH CIRCUIT FOR A SHORT TO GROUND

Ignition OFF.
Disconnect: BCM C2280C.

Measure:

Positive Lead	Measurement/Action	Negative Lead
C2280C-45		Ground

Is the resistance greater than 10, 000 ohms?

Yes : GO to A19
No : GO to A17

A17 CHECK THE REAR WINDOW DEFROST SWITCH CIRCUIT FOR A SHORT TO GROUND

Disconnect: Defrost Switch C241.

Measure:

Positive Lead	Measurement/Action	Negative Lead
C2280C-45		Ground

Is the resistance greater than 10, 000 ohms?

Yes : INSTALL a new rear window defrost switch.
No : REPAIR the circuit.

A18 CHECK THE REAR WINDOW DEFROST RELAY CONTROL CIRCUIT FOR A SHORT TO VOLTAGE

Ignition OFF.
Disconnect: Rear Window Defrost Relay.
Disconnect: BCM C2280B.
Ignition ON.

Measure:

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

Is any voltage present?

Yes : REPAIR the circuit.
No : GO to A19

A19 CHECK FOR CORRECT BODY CONTROL MODULE (BCM) 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 .
  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.