Circuit Description
The instrument panel integration module (IPM) communicates with the HVAC control module via the Driver HVAC Control Assembly Signal and Clock Signal data bus. This communication link is only used by the IPM and the HVAC control module.
Conditions for Running the DTC
The ignition is turned ON.
Conditions for Setting the DTC
| • | There is a loss of communications between the IPM and the HVAC control module. |
| • | The above conditions are present for 3 seconds. |
Action Taken When the DTC Sets
The heater and A/C system will be disabled.
Conditions for Clearing the DTC
| • | The DTC will become history if the IPM no longer detects a failure. |
| • | The history DTC will clear after 50 fault free ignition cycles. |
| • | The DTC can be cleared with a scan tool. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: HVAC Schematics Notice: The circuit terminates at a flat wire connector. Use the J 42675 Flat Wire Probe Adapter Kit in order to avoid damage and properly test the circuit. | ||||
1 | Did you perform the HVAC Diagnostic System Check? | -- | Go to Step 2 | |
Turn ON the ignition, with the engine OFF. Is the HVAC control module inoperative? | -- | Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections | |
3 |
Does the test lamp illuminate? | -- | Go to Step 4 | Go to Step 7 |
4 | Connect a test lamp between the ignition 3 voltage circuit and the ground circuit (connector pin location A1) of the HVAC control module. Does the test lamp illuminate? | -- | Go to Step 5 | Go to Step 8 |
5 |
Does the voltage measure near the specified value? | 1 V | Go to Step 6 | Go to Step 9 |
6 | Measure the frequency between the driver HVAC control assembly clock signal circuit of the HVAC control module and a good ground. Does the frequency measure near the specified value? | 930 Hz | Go to Step 11 | Go to Step 10 |
7 | Test the ignition 3 voltage circuit of the HVAC control module for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | -- |
8 | Test the ground circuit (connector pin location A1) of the HVAC control module for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | -- |
9 | Test the driver HVAC control assembly signal circuit for a short to voltage, a short to ground, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 12 |
10 | Test the driver HVAC control assembly clock signal circuit for a short to voltage, a short to ground, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 12 |
11 | Inspect for poor connections at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 13 |
12 | Inspect for poor connections at the harness connector of the instrument panel integration module (IPM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 14 |
13 | Replace the HVAC control module. Refer to HVAC Control Module Replacement . Did you complete the replacement? | -- | Go to Step 15 | -- |
14 |
Important : Perform the BCM Programming/RPO Configuration procedure in Body Control System for the replacement instrument panel integration module. Replace the instrument panel integration module. Refer to Instrument Panel Module Replacement in Body Control System. Did you complete the replacement? | -- | Go to Step 15 | -- |
15 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
