The HVAC control assembly sends input data through circuit 1880 to the HVAC programmer. The HVAC programmer uses this data to control the actuators on the HVAC module assembly.
| • | The ignition is on. | 
| • | A circuit is open or shorted. | 
Code 035 is set.
| • | Using a Scan Tool . | 
| • | A history DTC will clear when 40 consecutive ignition cycles have occurred without a malfunction. | 
| • | HVAC programmer battery voltage is interrupted. | 
Step  | Action  | Value(s)  | Yes  | No  | 
|---|---|---|---|---|
1  | 
 Install a jumper between HVAC control assembly terminal B1 and terminal B2. Does DTC 35 change status from CURRENT to HISTORY as displayed on the Scan Tool ?  | --  | Go to Step 3  | Go to Step 2  | 
2  | 
 Refer to Measuring Voltage in Wiring Systems. Does the voltage approximately equal the specified value?  | 8 V  | Go to Step 4  | Go to Step 5  | 
3  | Replace the HVAC control assembly. Refer to Control Assembly Replacement or refer to Control Assembly Replacement . Is the repair complete?  | --  | System OK  | --  | 
4  | 
 Refer to Probing Electrical Connectors in Wiring Systems. Does the voltage approximately equal the specified value?  | 3.5 V  | Go to Step 8  | Go to Step 9  | 
Backprobe terminal F12 and terminal E1 of the HVAC programmer harness connector. Refer to Probing Electrical Connectors in Wiring Systems. Does the voltage approximately equal the specified value?  | 8 V  | Go to Step 6  | Go to Step 7  | |
6  | Repair the open in CKT 1881. Refer to Wiring Repairs in Wiring Systems. Is the repair complete?  | --  | System OK  | --  | 
7  | 
 Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems. Is the repair complete?  | --  | System OK  | --  | 
8  | Backprobe the HVAC programmer harness connector terminal E16 and terminal E1. Refer to Probing Electrical Connectors in Wiring Systems. Does the voltage approximately equal the specified value?  | 3.5 V  | Go to Step 10  | Go to Step 11  | 
9  | 
 Is the repair complete?  | --  | System OK  | --  | 
10  | 
 Is the repair complete?  | --  | System OK  | --  | 
11  | Repair the open in CKT 1880. Refer to Wiring Repairs in Wiring Systems. Is the repair complete?  | --  | System OK  | --  |