Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. With the scan tool, read DTCs and record on the repair order.
2. Record the Environmental Data.
3. With the scan tool, erase DTCs.
4. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
5. With the scan tool, read HVAC Module DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - Perform the TESTING FOR AN INTERMITTENT CONDITION procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK THE Z911 CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. The ignition must be off when checking the continuity of a circuit.
2. Isolate the circuit(s) by disconnecting the Electronic Control Unit (ECU) and every component harness connector containing the circuit(s) being tested.
  NOTE:
  Use the wiring diagram as a guide to follow the path of the circuit.
3. Before measuring the resistance of any circuit, first measure the resistance between the two leads of the DVOM.
  NOTE:
  The meter leads can add resistance to the measurement value.
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 probing a circuit at an Electronic Control Unit (ECU) harness connector, always use an appropriate back probing tool to prevent any possible damage to the ECU terminals.

Is the resistance below 1.0 Ohm on both circuits?

Yes
- Go To 3
No
- Repair the Z911 circuit for an open or high resistance.
- Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
REPLACE THE BLOWER MOTOR POWER MODULE AND CHECK FOR THE DTC TO RETURN
1. Replace the Blower Motor Power Module in accordance with the Service Information. Refer to MOTOR, BLOWER, REMOVAL AND INSTALLATION or MOTOR, BLOWER, REAR, REMOVAL AND INSTALLATION .
2. Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
3. With the scan tool, read HVAC DTCs.
  Did the DTC return?
  
  Yes
  - Go To 4
  No
  - Replacing the Blower Motor Power Module corrected the condition.
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
  - Replace the HVAC Module in accordance with the Service information. Refer to MODULE, HVAC, REMOVAL AND INSTALLATION .
  - Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
  No
  - The wiring or poor connection problem has been repaired.
  - Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .