For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
DEFINITION: The temperature control operates with either too much or too little effort.
1 | Were you sent here from Symptoms or another diagnostic table? | Go to Step 2 | Go to Symptoms - HVAC Systems - Manual in HVAC Systems-Manual
2 | Verify that one of the following is a concern of the customer:

• | The temperature control operates with little or no resistance.

• | The HVAC outlet air temperature is constant, regardless of the temperature control setting.

• | While driving the vehicle the temperature control setting changes.

Does the temperature control operate too freely?

Go to Step 3

Go to Step 7

3 |

1. Idle the engine at normal operating temperature.
2. Cycle the temperature control from the coldest setting to the warmest setting.

Does the temperature change from cold to hot?

Go to Step 17

Go to Step 4

4 | Inspect the connections of the temperature control cable. Is the temperature control cable disconnected from the temperature door? | Go to Step 15 | Go to Step 5
5 | Inspect the temperature control cable and linkage at the temperature door, while operating the temperature controls. Does the temperature door move while operating the temperature controls? | Go to Step 22 | Go to Step 6
6 | Inspect the cable casing while operating the temperature controls. Does the cable casing move, instead of the cable, while operating the temperature controls? | Go to Step 19 | Go to Step 16
7 | Inspect the HVAC control module for any debris or obstructions that would increase the effort to operate the temperature controls. Are there any obstructions? | Go to Step 21 | Go to Step 8
8 |

1. Disconnect the temperature control cable from the temperature door.
2. Operate the HVAC control module with the temperature control cable disconnected.

Does the HVAC control module bind now?

Go to Step 10

Go to Step 9

9 | With the temperature control cable disconnected:

1. Manually operate the temperature door.
2. Inspect the door for binding.

Does the temperature door bind with the cable disconnected?

Go to Step 20

Go to Step 10

10 |

1. Disconnect the temperature control cable from the HVAC control assembly.
2. Operate the HVAC control module with the cable disconnected.

Does the HVAC control module bind now?

Go to Step 17

Go to Step 11

11 | With the temperature control cable disconnected at both ends:

1. Extend the cable in both directions.
2. Inspect the cable for binding.

Does the temperature control cable bind?

Go to Step 18

Go to Step 12

12 |

1. Inspect the temperature control cable for kinks or bends from incorrect routing.
2. Repair the cable or routing as necessary.

Does the temperature cable still bind?

Go to Step 18

Go to Step 13

13 | Operate the HVAC control module with the temperature control cable disconnected. Does the HVAC control module bind now? | Go to Step 17 | Go to Step 14
14 | Reassemble the temperature control system. Is the action complete? | Go to Step 22 | --
15 | Reconnect the temperature control cable to the temperature door linkage install the cable retainers. Is the action complete? | Go to Step 22 | --
16 | Repair the lack of heating or lack of cooling condition. Refer to Engine Fails To Reach Normal Operating Temperature . Is the action complete? | Go to Step 22 | --
17 | Replace the HVAC control assembly. Refer to Heater and Air Conditioning Control Replacement in HVAC Systems-Manual. Is the repair complete? | Go to Step 22 | --
18 | Replace the temperature control cable. Refer to Temperature Control Cable Replacement in HVAC-Systems Manual. Is the repair complete? | Go to Step 22 | --
19 | Secure the temperature control cable casing. Is the action complete? | Go to Step 22 | --
20 | Repair the binding door. Is the repair complete? | Go to Step 22 | --
21 | Remove the debris. Is the action complete? | Go to Step 22 | --
22 | Operate the system in order to verify the repair. Did you find and correct the condition? | System OK | Go to Step 2