Diagnostic Procedure

CAUTION: Use the correct probe adaptor(s) when making measurements. Failure to use the correct probe adaptor(s) may damage the connector.

DIAGNOSTIC PROCEDURE

PINPOINT TEST 15	THE HVAC MODULE DOES NOT RESPOND TO THE SCAN TOOL
STEP	INSPECTION	ACTION
1	CHECK THE HVAC MODULE VOLTAGE SUPPLY CIRCUIT FOR AN OPEN Key in OFF position. Disconnect: HVAC Module 0740-101. Key in ON position. Measure the voltage between the HVAC module 0740-101 pin 12, circuit (W), harness side and ground and between the HVAC module 0740-101 pin 13, circuit (W/R) harness side and ground. Are the voltages greater than 10 volts?	Yes	GO to the next step.
1		No	VERIFY the smart junction box (SJB) fuse 15 (10A) or fuse 37 (10A) is OK. If OK, REPAIR the circuit in question. CLEAR the DTCs. REPEAT the network test with the scan tool.
2	CHECK THE HVAC MODULE GROUND CIRCUIT FOR AN OPEN Key in OFF position. Measure the resistance between the HVAC module 0740-101 pin 23, circuit (B/L), harness side and ground. Is the resistance less than 5 ohms?	Yes	GO to the next step.
2		No	REPAIR the circuit. CLEAR the DTCs. REPEAT the network test with the scan tool.
3	CHECK THE MS-CAN CIRCUITS BETWEEN THE HVAC MODULE AND THE DATA LINK CONNECTOR (DLC) FOR AN OPEN Measure the resistance between the HVAC module 0740-101 pin 25, circuit (GY/O), harness side and the DLC D-01 pin 3, circuit (GY/O), harness side. Measure the resistance between the HVAC module 0740-101 pin 26, circuit (V/O), harness side and the DLC D-01 pin 11, circuit (V/O), harness side. Are the resistances less than 5 ohms?	Yes	GO to the next step.
3		No	REPAIR the circuit in question. REPEAT the network test with the scan tool.
4	CHECK FOR CORRECT HVAC MODULE OPERATION Disconnect the HVAC module connectors. Check for: corrosion damaged pins pushed-out pins Connect the HVAC module connectors and make sure they seat correctly. Operate the system and verify the concern is still present. Is the concern still present?	Yes	INSTALL a new HVAC module. See CLIMATE CONTROL MODULE REMOVAL/INSTALLATION . CONNECT the battery ground cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
4		No	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CONNECT the battery ground cable. CLEAR the DTCs. REPEAT the network test with the scan tool.