B1034

B1034-Infrared Temperature Sensor Input Circuit Low






For a complete wiring diagram, refer to.

• When Monitored: With the ignition on.

• Set Condition: The Infrared Temperature Sensor pulse width modulated (PWM) signal to the A/C Heater Control equals 0.0 volts for a continuous period of 120 seconds. If the A/C Heater Control detects a valid PWM signal, the DTC will change from active to stored and will stay stored for 100 ignition cycles.






Always perform the HVAC Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to => Non-DTC Based
Diagnostics. HVAC Pre-Diagnostic Troubleshooting Procedure

Test Step 1 - CHECK IF DTC IS ACTIVE

• Ignition on, engine not running.

• With the scan tool, read HVAC DTCs after a minimum of 120 seconds.

Is this DTC active?

Yes

• Go to Test Step 2 => [ Test Step 2 - CHECK THE (F921) FUSED RUN RELAY OUTPUT CIRCUIT FOR
AN OPEN ]

No

• Go to Test Step 6 => [ Test Step 6 - CHECK THE WIRING AND CONNECTORS ]

Test Step 2 - CHECK THE (F921) FUSED RUN RELAY OUTPUT CIRCUIT FOR AN OPEN







• Turn the ignition off to the lock position.

• Disconnect the Infrared Sensor harness connector.

• Ignition on, engine not running.

• With a test light connected to ground, check the (F921) Fused Run Relay Output circuit.

• The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.

Does the test light illuminate brightly?

Yes

• Go to Test Step 3 => [ Test Step 3 - CHECK THE (C83) INFRARED SENSOR SIGNAL CIRCUIT FOR
A SHORT TO GROUND ]

No

• Repair the (F921) Fused Run Relay Output circuit for an open.

• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

Test Step 3 - CHECK THE (C83) INFRARED SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND







• Turn the ignition off to the lock position.

• Disconnect the A/C Heater Control harness connector.

• Measure the resistance between ground and the (C83) Infrared Sensor Signal circuit.

Is the resistance below 100k Ohms?

Yes

• Repair the (C83) Infrared Sensor Signal circuit for a short to ground.

• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

No

• Go to Test Step 4 => [ Test Step 4 - CHECK THE (C83) INFRARED SENSOR SIGNAL CIRCUIT FOR
AN OPEN ]


Test Step 4 - CHECK THE (C83) INFRARED SENSOR SIGNAL CIRCUIT FOR AN OPEN







• Measure the resistance of the (C83) Infrared Sensor Signal circuit between the A/C Heater Control harness connector.

Is the resistance below 100k Ohms?

Yes

• Repair the (C83) Infrared Sensor Signal circuit for an open.

• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

No

• Go to Test Step 5 => [ Test Step 5 - CHECK THE INFRARED SENSOR ]

Test Step 5 - CHECK THE INFRARED SENSOR

• Replace the Infrared Sensor.

• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

Did the DTC reset performing the HVAC Verification Test?

Yes

• Replace and program the A/C Heater Control.

• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

No

• Test complete.

Test Step 6 - CHECK THE WIRING AND CONNECTORS

• The conditions necessary to set the DTC are not present at this time.

• Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.

• Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.

• With the scan tool, check the Environmental Data to help identify the conditions in which the DTC was set.

Were there any problems found?

Yes

• Repair as necessary.

• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

No

• Test complete.