Diagnostic Test

WARNING: This page is about a different car, the 2016 Jeep Wrangler and 2015 Jeep Wrangler. However, it is still accessible from the selected car via links, so may be relevant.

CHECK IF DTC IS ACTIVE
1. Ignition on, engine not running.
2. With the scan tool, read HVAC DTCs.
  Is this DTC active?
  
  Yes
  - Go To 2
  No
  - Go To 6
CHECK THE (G39) SUN SENSOR 1 SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE

Fig 1: Checking Sun Sensor 1 Signal Circuit For A Short To Voltage
Courtesy of CHRYSLER GROUP, LLC
1. Turn the ignition off to the lock position.
2. Disconnect the Sun Sensor harness connector.
3. Disconnect the A/C Heater Control harness connector.
  NOTE:
  Check connectors - Clean/repair as necessary.
4. Ignition on, engine not running.
5. Check the voltage of the (G39) Sun Sensor 1 Signal circuit.
  Is there any voltage present?
  
  Yes
  - Repair the (G39) Sun Sensor 1 Signal circuit for an short to voltage.
  - Perform the HVAC VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 3
CHECK THE (G39) SUN SENSOR 1 SIGNAL CIRCUIT FOR AN OPEN

Fig 2: Checking Sun Sensor 1 Signal Circuit For An Open
Courtesy of CHRYSLER GROUP, LLC
1. Turn the ignition off to the lock position.
2. Measure the resistance of the (G39) Sun Sensor 1 Signal circuit between the A/C Heater Control harness connector and the Sun Sensor harness connector.
  Is the resistance above 5.0 Ohms?
  
  Yes
  - Repair the (G39) Sun Sensor 1 Signal circuit for an open.
  - Perform the HVAC VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 4
CHECK THE (C121) SENSOR GROUND CIRCUIT FOR AN OPEN

Fig 3: Checking Sensor Ground Circuit For An Open
Courtesy of CHRYSLER GROUP, LLC
1. Measure the resistance of the (C121) Sensor Ground circuit between the A/C Heater Control C1 harness connector and the Sun Sensor harness connector.
  Is the resistance above 5.0 Ohms?
  
  Yes
  - Repair the (C121) Sensor Ground circuit for an open.
  - Perform the HVAC VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 5
CHECK THE SUN SENSOR AND A/C HEATER CONTROL
1. Turn the ignition off to the lock position.
2. Replace the Sun Sensor in accordance with the Service Information. Refer to SENSOR, SUN, REMOVAL .
3. Perform the HVAC VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  Did the DTC reset during or after the HVAC Verification Test?
  
  Yes
  - Replace and program the A/C Heater Control in accordance with the Service Information. Refer to CONTROL, A/C AND HEATER, REMOVAL .
  - Perform the HVAC VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Test complete.
CHECK THE WIRING AND CONNECTORS
1. The conditions necessary to set the DTC are not present at this time.
2. Using the scan tool, check the Environmental Data to help identify the conditions in which the DTC was set.
3. 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.
4. Wiggle the wiring and connectors while checking for shorted and open circuits.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the HVAC VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Test complete.