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Home >> Jeep >> 2024 >> Wagoneer Carbide, RWD >> Repair and Diagnosis >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> Heating And Air Conditioning (ATC) - DTCS B11C3-00 To B11CC-00 >> DTC Troubleshooting >> B11CB-15-Front/Left Temperature Door 1 Control-Circuit Short To Battery Or Open >> Diagnostic Test

Diagnostic Test

  1. READ AND RECORD DTCS AND ENVIRONMENTAL DATA - ERASE DTCS AND CHECK FOR THE DTC TO RETURN 
    1. With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
    2. With the scan tool, run a Vehicle Scan Report or record the Environmental Data.
    3. With the scan tool, erase DTCs.
    4. Turn the ignition off for at least 10.0 seconds.
    5. Turn the ignition on.
    6. Using the recorded Environmental Data and the When Monitored Conditions, operate the vehicle in the conditions that set the DTC.
    7. With the scan tool, read DTCs.

      Did the DTC return?

      Yes 

      • Go To  3

      No 

      • Go To  2
  2. PERFORM HVAC ACTUATOR CALIBRATION TEST AND CHECK FOR THE DTC TO RETURN 
    1. With the scan tool, perform the HVAC Actuator Calibration Test and recheck DTCs.

      Did the DTC return?

      Yes 

      • Go To Next Step.

      No 

  3. CHECK THE 5V SUPPLY CIRCUIT FOR PROPER VOLTAGE AT THE DOOR ACTUATOR HARNESS CONNECTOR 
    1. Turn the ignition off.
    2. Disconnect the harness connector at the component of the circuit being tested. Check the disconnected connectors and related harnesses for damage, corrosion, and loose fitting terminals. Note:  The Electronic Control Unit (ECU) harness connector should still be connected during this test step.
    3. Turn the ignition on.
    4. Set the Digital Volt-Ohm Meter (DVOM) to measure Direct Current (DC) voltage.
    5. Connect the negative lead of the DVOM to a known good ground.
    6. With the positive lead of the DVOM, measure the voltage of the circuit being tested at the component harness connector.

      Is the voltage between 4.8 and 5.2 volts?

      Yes 

      • Go To  4

      No 

      • Go To  11
  4. CHECK THE SIGNAL RETURN CIRCUIT AT THE DOOR ACTUATOR HARNESS CONNECTOR 
    1. Turn the ignition off.
    2. Disconnect the harness connector at the component of the circuit being tested. Check the disconnected connectors and related harnesses for damage, corrosion, and loose fitting terminals. Note:  The Electronic Control Unit (ECU) harness connector should still be connected during this test step.
    3. Turn the ignition on.
    4. Set the Digital Volt-Ohm Meter (DVOM) to measure Direct Current (DC) voltage.
    5. Connect the negative lead of the DVOM to the Signal Return circuit at the component harness connector.
    6. Connect the positive lead of the DVOM to the 5-volt Supply circuit at the component harness connector.

      Is the voltage between 4.8 and 5.2 volts?

      Yes 

      • Go To  5

      No 

      • Go To  9
  5. CHECKING THE DOOR SENSOR SIGNAL 
    1. Turn the ignition off.
    2. Disconnect the harness connector at the component of the circuit being tested. Check the disconnected connectors and related harnesses for damage, corrosion, and loose fitting terminals. Note:  The Electronic Control Unit (ECU) harness connector should still be connected during this test step.
    3. Turn the ignition on and check for Door Control Short To Battery/Open DTCs.
    4. Connect a jumper wire between the Signal Return circuit and the Sensor Signal circuit at the component harness connector. Check for Door Control Short To Ground/Low DTCs
      NOTE:

      When back-probing a circuit at a harness connector, always use an appropriate back probing tool to prevent damage to the connector terminals.

      Did the scan tool display Short To Battery/High DTC when actuator was disconnected then switch to Short To Ground/Low when jumped to Signal Return?

      Yes 

      No 

      • Go To  6
  6. ISOLATE AND CHECK THE DOOR SIGNAL CIRCUIT FOR AN OPEN OR HIGH RESISTANCE 
    1. The ignition must be off when checking the continuity of a circuit.
    2. Isolate the circuit by disconnecting the ECU and the component harness connectors containing the circuit being tested. Note:  Use the wiring diagram as a guide to follow the path of the circuit. Check the disconnected connectors and related harnesses for damage, corrosion, and loose fitting terminals.
    3. Before testing a circuit, measure the resistance between the two leads of the DVOM. Note:  Resistance in the meter leads can cause an error in the test results.
    4. Measure the resistance of the Door Sensor Signal circuit between the ECU and the Door Actuator harness connector.
      NOTE:

      When back-probing a circuit at a harness connector, always use an appropriate back probing tool to prevent damage to the connector terminals.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Go To  7

      No 

      • Repair the circuit for an open or high resistance.
      • Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
  7. ISOLATE AND CHECK THE DOOR SIGNAL CIRCUIT FOR A SHORT TO GROUND 
    1. The ignition must be off when checking a circuit for continuity to ground.
    2. Isolate the circuit by disconnecting the ECU and the component harness connectors containing the circuit being tested. Note:  Use the wiring diagram as a guide to follow the path of the circuit. Check the disconnected connectors and related harnesses for damage, corrosion, and loose fitting terminals.
    3. Connect the negative lead of the DVOM to a known good ground.
    4. With the positive lead of the DVOM, probe the circuit being tested at the component harness connector and check for continuity between the circuit and ground.
      NOTE:

      When back-probing a circuit at a harness connector, always use an appropriate back probing tool to prevent damage to the connector terminals.

      Is there continuity between ground and the circuit being tested?

      Yes 

      • Repair the circuit for a short to ground. Use the wiring diagram as a guide to trace the circuit and identify any in-line connectors that may help isolate the location of the short.
      • Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .

      No 

      • Go To  8
  8. ISOLATE AND CHECK THE DOOR SIGNAL CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT AT THE HVAC MODULE HARNESS CONNECTOR 
    1. The ignition must be off when performing a resistance check to find a short between circuits.
    2. Isolate the circuit by disconnecting the ECU and the component harness connectors containing the circuit being tested. Note:  Use the wiring diagram as a guide to follow the path of the circuit. Check the disconnected connectors and related harnesses for damage, corrosion, and loose fitting terminals.
    3. Connect one lead of the DVOM to the circuit being tested at the ECU harness connector.
    4. With the other lead of the DVOM probe all other circuits at the ECU harness connector.
      NOTE:

      When back-probing a circuit at a harness connector, always use an appropriate back probing tool to prevent damage to the connector terminals.

      Is there continuity between the circuit being tested and any other circuit?

      Yes 

      • Repair the circuit for a short to another circuit. Use the wiring diagram as a guide to trace the circuits and look for any in-line connectors to help isolate the location of the short.
      • Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .

      No 

      • Go To  14
  9. ISOLATE AND CHECK THE SIGNAL RETURN CIRCUIT FOR AN OPEN OR HIGH RESISTANCE 
    1. The ignition must be off when checking the continuity of a circuit.
    2. Isolate the circuit by disconnecting the ECU and the component harness connectors containing the circuit being tested. Note:  Use the wiring diagram as a guide to follow the path of the circuit. Check the disconnected connectors and related harnesses for damage, corrosion, and loose fitting terminals.
    3. Before testing a circuit, measure the resistance between the two leads of the DVOM. Note:  Resistance in the meter leads can cause an error in the test results.
    4. Connect one lead of the DVOM to the circuit being tested at the component harness connector.
    5. Connect the other lead to the circuit being tested at the ECU harness connector and measure the resistance of the circuit.
      NOTE:

      When back-probing a circuit at a harness connector, always use an appropriate back probing tool to prevent damage to the connector terminals.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Go To  14

      No 

      • Repair the circuit for an open or high resistance.
      • Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
  10. REPLACE THE DOOR ACTUATOR AND CHECK FOR THE DTC TO RETURN 
    1. Replace the Associated Door Actuator in accordance with the Service Information.
    2. Connect the Door Actuator, ECU, and any other disconnected harness connectors.
    3. Turn the ignition on.
    4. With the scan tool, erase DTCs.
    5. Using the Environmental Data and When Monitored conditions, operate the vehicle within the conditions that set the DTC.
    6. With the scan tool, read DTCs.

      Did the DTC return?

      Yes 

      • Go To  14

      No 

      • Replacing the Door Actuator corrected the condition.
      • Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
  11. ISOLATE AND CHECK THE 5V SUPPLY CIRCUIT FOR AN OPEN OR HIGH RESISTANCE 
    1. The ignition must be off when checking the continuity of a circuit.
    2. Isolate the circuit by disconnecting the ECU and the component harness connectors containing the circuit being tested. Note:  Use the wiring diagram as a guide to follow the path of the circuit. Check the disconnected connectors and related harnesses for damage, corrosion, and loose fitting terminals.
    3. Before testing a circuit, measure the resistance between the two leads of the DVOM. Note:  Resistance in the meter leads can cause an error in the test results.
    4. Connect one lead of the DVOM to the circuit being tested at the component harness connector.
    5. Connect the other lead to the circuit being tested at the ECU harness connector and measure the resistance of the circuit.
      NOTE:

      When back-probing a circuit at a harness connector, always use an appropriate back probing tool to prevent damage to the connector terminals.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Go To  12

      No 

      • Repair the circuit for an open or high resistance.
      • Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
  12. ISOLATE AND CHECK THE 5V SUPPLY CIRCUIT FOR A SHORT TO GROUND 
    1. The ignition must be off when checking a circuit for continuity to ground.
    2. Isolate the circuit by disconnecting the ECU and the component harness connectors containing the circuit being tested. Note:  Use the wiring diagram as a guide to follow the path of the circuit. Check the disconnected connectors and related harnesses for damage, corrosion, and loose fitting terminals.
    3. Connect the negative lead of the DVOM to a known good ground.
    4. With the positive lead of the DVOM, probe the circuit being tested at the component harness connector and check for continuity between the circuit and ground.
      NOTE:

      When back-probing a circuit at a harness connector, always use an appropriate back probing tool to prevent damage to the connector terminals.

      Is there continuity between ground and the circuit being tested?

      Yes 

      • Repair the circuit for a short to ground. Use the wiring diagram as a guide to trace the circuit and identify any in-line connectors that may help isolate the location of the short.
      • Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .

      No 

      • Go To  13
  13. ISOLATE AND CHECK THE 5V SUPPLY CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT AT THE HVAC MODULE HARNESS CONNECTOR 
    1. The ignition must be off when performing a resistance check to find a short between circuits.
    2. Isolate the circuit by disconnecting the ECU and the component harness connectors containing the circuit being tested. Note:  Use the wiring diagram as a guide to follow the path of the circuit. Check the disconnected connectors and related harnesses for damage, corrosion, and loose fitting terminals.
    3. Connect one lead of the DVOM to the circuit being tested at the ECU harness connector.
    4. With the other lead of the DVOM probe all other circuits at the ECU harness connector.
      NOTE:

      When back-probing a circuit at a harness connector, always use an appropriate back probing tool to prevent damage to the connector terminals.

      Is there continuity between the circuit being tested and any other circuit?

      Yes 

      • Repair the circuit for a short to another circuit. Use the wiring diagram as a guide to trace the circuits and look for any in-line connectors to help isolate the location of the short.
      • Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .

      No 

      • Go To  14
  14. CHECK RELATED HARNESS CONNECTIONS 
    1. Disconnect all HVAC Module harness connectors.
    2. Disconnect all related in-line harness connections (if equipped).
    3. Disconnect the related component harness connectors.
    4. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
      • Proper connector installation.
      • Damaged connector locks.
      • Corrosion.
      • Other signs of water intrusion.
      • Weather seal damage (if equipped).
      • Bent terminals.
      • Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
      • Terminals that have been pushed back into the connector cavity.
      • Perform a terminal drag test on each connector terminal to verify proper terminal tension.

      Repair any conditions that are found.

    5. Reconnect all HVAC Module harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
    6. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
    7. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
    8. With the scan tool, erase DTCs.
    9. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
    10. With the scan tool, read HVAC Module DTCs.

      Did the DTC return?

      Yes 

      No 

      • The wiring or poor connection problem has been repaired.
      • Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
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