
Symptom:
REAR BLEND POT CIRCUIT SHORT (ACTIVE) - MANUAL A/C
When Monitored and Set Condition:
REAR BLEND POT CIRCUIT SHORT (ACTIVE) - MANUAL A/C
When Monitored: When the ignition is on.
Set Condition: This DTC will set if the Rear Blower Rear Control Switch, Rear Blend
Potentiometer/5 Volt Supply/Rear Temperature Feedback Signal circuit is shorted low or
high.
POSSIBLE CAUSES
REAR BLEND POTENTIOMETER SHORTED
5 VOLT SUPPLY CIRCUIT SHORTED TO REAR TEMPERATURE RETURN CIRCUIT
5 VOLT SUPPLY CIRCUIT SHORTED TO GROUND
REAR TEMPERATURE FEEDBACK SIGNAL CIRCUIT SHORTED TO GROUND
A/C - HEATER CONTROL MODULE
5 VOLT SUPPLY CIRCUIT SHORTED TO REAR TEMPERATURE FEEDBACK SIGNAL CIRCUIT
5 VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE
REAR TEMPERATURE FEEDBACK SIGNAL CIRCUIT SHORTED TO VOLTAGE
REAR TEMPERATURE FEEDBACK SIGNAL CKT SHORTED TO REAR TEMPERATURE RETURN
CKT
A/C - HEATER CONTROL MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition off.
Disconnect the Rear Blower Rear Control Switch C2 harness connector.
Turn the ignition on.
With the DRBIIItin Input/Output Display, read the Rear Blend position status.
What is the Rear Blend position status?All
Open
Replace the Rear Blower Rear Control Switch in accordance with
the Service Information.
Perform BODY VERIFICATION TEST - VER 1.
Full Cold
Go To 2
Full Hot
Go To 5
556
HEATING & A/C

TEST ACTION APPLICABILITY
2 Turn the ignition off.
Disconnect the A/C - Heater Control Module C1 harness connector.
Disconnect the Rear Blower Rear Control Switch C2 harness connector.
Measure the resistance between the 5 Volt Supply circuit and the Rear Temperature
Return circuit.
Is the resistance above 10K ohms?All
Ye s®Go To 3
No®Repair the 5 Volt Supply circuit for a short to the Rear Temper-
ature Return circuit.
Perform BODY VERIFICATION TEST - VER 1.
3 Turn the ignition off.
Disconnect the A/C - Heater Control Module C1 harness connector.
Disconnect the Rear Blower Rear Control Switch C2 harness connector.
Measure the resistance between ground and the 5 Volt Supply circuit.
Is the resistance above 10K ohms?All
Ye s®Go To 4
No®Repair the 5 Volt Supply circuit for a short to ground.
Perform BODY VERIFICATION TEST - VER 1.
4 Turn the ignition off.
Disconnect the A/C - Heater Control Module C1 harness connector.
Disconnect the Rear Blower Rear Control Switch C2 harness connector.
Measure the resistance between ground and the Rear Temperature Feedback Signal
circuit.
Is the resistance above 10K ohms?All
Ye s®Replace the A/C - Heater Control Module in accordance with the
Service Information.
Perform BODY VERIFICATION TEST - VER 1.
No®Repair the Rear Temperature Feedback Signal circuit for a short
to ground.
Perform BODY VERIFICATION TEST - VER 1.
5 Turn the ignition off.
Disconnect the A/C - Heater Control Module C1 harness connector.
Disconnect the Rear Blower Rear Control Switch C2 harness connector.
Measure the resistance between the 5 Volt Supply circuit and the Rear Temperature
Feedback Signal circuit.
Is the resistance above 10K ohms?All
Ye s®Go To 6
No®Repair the 5 Volt Supply circuit for a short to the Rear Temper-
ature Feedback Signal circuit.
Perform BODY VERIFICATION TEST - VER 1.
557
HEATING & A/C
REAR BLEND POT CIRCUIT SHORT (ACTIVE) - MANUAL A/C ÐContinued

TEST ACTION APPLICABILITY
6 Turn the ignition off.
Disconnect the A/C - Heater Control Module C1 harness connector.
Disconnect the Rear Blower Rear Control Switch C2 harness connector.
Turn the ignition on.
Measure the voltage between the 5 Volt Supply circuit and ground.
Is there any voltage present?All
Ye s®Repair the 5 Volt Supply circuit for a short to voltage.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 7
7 Turn the ignition off.
Disconnect the A/C - Heater Control Module C1 harness connector.
Disconnect the Rear Blower Rear Control Switch C2 harness connector.
Turn the ignition on.
Measure the voltage between the Rear Temperature Feedback Signal circuit and
ground.
Is there any voltage present?All
Ye s®Repair the Rear Temperature Feedback Signal circuit for a short
to voltage.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 8
8 Turn the ignition off.
Disconnect the A/C - Heater Control Module C1 harness connector.
Disconnect the Rear Blower Rear Control Switch C2 harness connector.
Measure the resistance between the Rear Temperature Feedback Signal circuit and
the Rear Temperature Return circuit.
Is the resistance above 10K ohms?All
Ye s®Replace the A/C - Heater Control Module in accordance with the
Service Information.
Perform BODY VERIFICATION TEST - VER 1.
No®Repair the Rear Temperature Feedback Signal circuit for a short
to the Rear Temperature Return circuit.
Perform BODY VERIFICATION TEST - VER 1.
558
HEATING & A/C
REAR BLEND POT CIRCUIT SHORT (ACTIVE) - MANUAL A/C ÐContinued

TEST ACTION APPLICABILITY
4 Turn the ignition on.
With the DRBIIIt, erase HVAC DTCs.
Cycle the ignition switch and wait approximately 1 minute.
With the DRBIIIt, read HVAC DTC's.
Did this DTC reset?All
Ye s®Replace the A/C - Heater Control Module in accordance with the
Service Information.
Perform BODY VERIFICATION TEST - VER 1.
No®Test Complete.
560
HEATING & A/C
TX FAILURE (ACTIVE) - MANUAL A/C ÐContinued

TEST ACTION APPLICABILITY
3 Turn the ignition on.
Disconnect the Fuel Tank Module harness connector.
Measure the resistance of the Ground circuits in the Fuel Tank Module harness
connector.
Is the resistance below 5.0 ohms for both measurements?All
Ye s®Go To 4
No®Repair the Ground circuit for an open.
Perform BODY VERIFICATION TEST - VER 1.
4 Turn the ignition off.
Disconnect the Fuel Tank Module harness connector.
Turn the ignition on.
With the DRBIIItin Body Computer then Sensors, monitor the Fuel Sensor.
Using a jumper wire, jumper the Fuel Level Sensor Signal circuit to the ground
circuit in the Fuel Tank Module harness connector.
Does the DRB display below 0.5 volt?All
Ye s®Replace the Fuel Level Sending Unit.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 5
5 Turn the ignition off.
Disconnect the Fuel Tank Module harness connector.
Disconnect the BCM C3 harness connector.
Measure the resistance of the Fuel Level Sensor Signal circuit between the Fuel Tank
Module harness connector and the BCM harness connector.
Is the resistance below 5.0 ohms?All
Ye s®Go To 6
No®Repair the Fuel Level Sensor Signal for an open.
Perform BODY VERIFICATION TEST - VER 1.
6 If there are no possible causes remaining, view repair. All
Repair
Replace the Body Control Module.
Perform BODY VERIFICATION TEST - VER 1.
7WARNING: WHEN THE ENGINE IS OPERATING, DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE
PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.
NOTE: The conditions that set the DTC are not present at this time. The
following list may help in identifying the intermittent condition.
With the engine running at normal operating temperature, monitor the DRB
parameters related to the DTC while wiggling the wiring harness. Look for param-
eter values to change and/or a DTC to set.
Refer to any Technical Service Bulletins (TSB) that may apply.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wiring harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Were any of the above conditions present?All
Ye s®Repair as necessary
Perform BODY VERIFICATION TEST - VER 1.
No®Test Complete.
573
INSTRUMENT CLUSTER
FUEL LEVEL SENDING UNIT INPUT OPEN ÐContinued

TEST ACTION APPLICABILITY
4 If there are no possible causes remaining, view repair. All
Repair
Replace the Body Control Module.
Perform BODY VERIFICATION TEST - VER 1.
5WARNING: WHEN THE ENGINE IS OPERATING, DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE
PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.
NOTE: The conditions that set the DTC are not present at this time. The
following list may help in identifying the intermittent condition.
With the engine running at normal operating temperature, monitor the DRB
parameters related to the DTC while wiggling the wiring harness. Look for param-
eter values to change and/or a DTC to set.
Refer to any Technical Service Bulletins (TSB) that may apply.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wiring harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Were any of the above conditions present?All
Ye s®Repair as necessary
Perform BODY VERIFICATION TEST - VER 1.
No®Test Complete.
575
INSTRUMENT CLUSTER
FUEL LEVEL SENDING UNIT INPUT SHORT ÐContinued

TEST ACTION APPLICABILITY
3 Turn the ignition off.
Disconnect the Instrument Cluster harness connector.
Disconnect the BCM C4 harness connector.
Measure the resistance of the Instrument Cluster Wake Up Sense circuit between the
BCM C4 harness connector and the MIC harness connector.
Is the resistance below 5.0 ohms?All
Ye s®Go To 4
No®Repair the Instrument Cluster Wake Up Sense circuit for an
open.
Perform BODY VERIFICATION TEST - VER 1.
4 Turn the ignition off.
Disconnect the Instrument Cluster harness connector.
Disconnect the BCM C4 harness connector.
Measure the resistance of the Instrument Cluster Wake Up Sense circuit in the MIC
harness connector to ground.
Is the resistance below 5.0 ohms?All
Ye s®Repair the Instrument Cluster Wake Up Sense circuit for a
shorted to ground.
Perform BODY VERIFICATION TEST - VER 1.
No®Replace the Instrument Cluster.
Perform BODY VERIFICATION TEST - VER 1.
5WARNING: WHEN THE ENGINE IS OPERATING, DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE
PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.
NOTE: The conditions that set the DTC are not present at this time. The
following list may help in identifying the intermittent condition.
With the engine running at normal operating temperature, monitor the DRB
parameters related to the DTC while wiggling the wiring harness. Look for param-
eter values to change and/or a DTC to set.
Refer to any Technical Service Bulletins (TSB) that may apply.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wiring harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Were any of the above conditions present?All
Ye s®Repair as necessary
Perform BODY VERIFICATION TEST - VER 1.
No®Test Complete.
577
INSTRUMENT CLUSTER
IOD WAKEUP CLUSTER OUTPUT OPEN ÐContinued

TEST ACTION APPLICABILITY
3 Turn the ignition off.
Disconnect the BCM C4 harness connector.
Disconnect the Instrument Cluster harness connector.
Turn the ignition on.
Using a 12-volt test light connected to ground, probe the Instrument Cluster Wake
Up Sense circuit.
Is the test light illuminated?All
Ye s®Repair the Instrument Cluster Wake Up Sense circuit for a short
to voltage.
Perform BODY VERIFICATION TEST - VER 1.
No®Replace the Instrument Cluster.
Perform BODY VERIFICATION TEST - VER 1.
4WARNING: WHEN THE ENGINE IS OPERATING, DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE
PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.
NOTE: The conditions that set the DTC are not present at this time. The
following list may help in identifying the intermittent condition.
With the engine running at normal operating temperature, monitor the DRB
parameters related to the DTC while wiggling the wiring harness. Look for param-
eter values to change and/or a DTC to set.
Refer to any Technical Service Bulletins (TSB) that may apply.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wiring harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Were any of the above conditions present?All
Ye s®Repair as necessary
Perform BODY VERIFICATION TEST - VER 1.
No®Test Complete.
579
INSTRUMENT CLUSTER
IOD WAKEUP CLUSTER OUTPUT SHORT ÐContinued