The numbers below refer to the step numbers on the diagnostic table.
This step checks for proper cooling system operation.
This step checks for proper air temperature actuator movement.
The voltage will vary between 0-12 volts during normal operation. The front auxiliary HVAC control assembly connector must be connected during this step. This checks for proper operation of the air temperature actuator door control circuit and the front auxiliary HVAC control assembly.
The voltage will vary between 0-12 volts during normal operation. The front auxiliary HVAC control assembly connector must be connected during this step. This checks for proper operation of the air temperature actuator door control circuit and the front auxiliary HVAC control assembly.
The auxiliary blower motor switch control circuit should not have continuity to ground when the front auxiliary HVAC control assembly is in any position except REAR CNTL.
The voltage will vary between 0-12 volts during normal operation. The rear auxiliary HVAC control assembly connector must be connected during this step. This checks for proper operation of the air temperature actuator door control circuit and the rear auxiliary HVAC control assembly.
This step checks complete auxiliary air temperature door control circuit from the front HVAC control assembly to the auxiliary HVAC control processor to the auxiliary air temperature actuator.
Step | Action | Value(s) | Yes | No | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: HVAC Schematics Connector End View Reference: HVAC Connector End Views DEFINITION: The air temperature cannot be adjusted from one or both auxiliary controls or the auxiliary cooling is insufficient. | ||||||||||||||||
1 | Did you review the HVAC operation and perform the necessary inspections? | -- | Go to Step 2 | |||||||||||||
2 |
Does the auxiliary blower motor operate in any of the speed positions? | -- | Go to Step 3 | |||||||||||||
3 | Does the auxiliary blower motor operate correctly for each speed position? | -- | Go to Step 4 | |||||||||||||
Inspect the cooling system for the following conditions:
Did you find and correct the condition? | -- | Go to Step 37 | Go to Step 5 | |||||||||||||
5 |
Does the A/C compressor operate? | -- | Go to Step 6 | |||||||||||||
6 | Does the Auxiliary Too Cold in Vehicle condition happen with front and rear auxiliary HVAC control assemblies? | -- | Go to Step 9 | Go to Step 7 | ||||||||||||
7 | Does the Auxiliary Too Cold in Vehicle condition happen with front auxiliary HVAC control assembly? | -- | Go to Step 13 | Go to Step 8 | ||||||||||||
8 | Does the Auxiliary Too Cold in Vehicle condition happen with rear HVAC control assembly? | -- | Go to Step 16 | Go to Too Cold in Vehicle | ||||||||||||
Does the air temperature actuator move with a smooth transition between COLD and HOT? | -- | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 10 | |||||||||||||
Does the voltage measure within the specified values with a smooth transition between COLD and HOT? | 0-12 V | Go to Step 11 | Go to Step 20 | |||||||||||||
11 | Connect a test lamp between the ignition 3 voltage circuit and ground circuit of the auxiliary air temperature actuator. Does the test lamp illuminate? | -- | Go to Step 19 | Go to Step 12 | ||||||||||||
12 | Connect a test lamp between the ignition 3 voltage circuit and good ground. Does the test lamp illuminate? | -- | Go to Step 21 | Go to Step 22 | ||||||||||||
Does the voltage measure within the specified values with a smooth transition between COLD and HOT? | 0-12 V | Go to Step 14 | Go to Step 23 | |||||||||||||
Does the test lamp illuminate? | -- | Go to Step 24 | Go to Step 15 | |||||||||||||
15 | Connect a test lamp between the ignition 3 voltage circuit and good ground . Does the test lamp illuminate? | -- | Go to Step 30 | Go to Step 25 | ||||||||||||
Does the voltage measure within the specified values with a smooth transition between COLD and HOT? | 0-12 V | Go to Step 17 | Go to Step 26 | |||||||||||||
17 |
Does the test lamp illuminate? | -- | Go to Step 25 | Go to Step 18 | ||||||||||||
18 | Connect a test lamp between the ignition 3 voltage circuit of the rear auxiliary HVAC control assembly and good ground. Does the test lamp illuminate? | -- | Go to Step 27 | Go to Step 28 | ||||||||||||
19 | Inspect the auxiliary air temperature door and the auxiliary air temperature actuator for the following conditions:
Did you find and correct the condition? | -- | Go to Step 37 | Go to Step 29 | ||||||||||||
Test the auxiliary air temperature door control circuit of the auxiliary air temperature actuator from the front auxiliary HVAC control assembly to the auxiliary air temperature actuator for an open, high resistance, short to ground, or short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 37 | Go to Step 25 | |||||||||||||
21 | Test the ground circuit of the auxiliary air temperature actuator for an open or high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 37 | Go to Step 29 | ||||||||||||
22 | Test the ignition 3 voltage circuit for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 37 | Go to Step 29 | ||||||||||||
23 | Test the auxiliary air temperature door control circuit of the auxiliary air temperature actuator from the front auxiliary HVAC control assembly to the auxiliary HVAC control processor for an open, high resistance, short to ground, and short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 37 | Go to Step 30 | ||||||||||||
24 | Test the auxiliary blower motor switch control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 37 | Go to Step 30 | ||||||||||||
25 | Test the ignition 3 voltage circuit of the auxiliary HVAC control processor for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 37 | Go to Step 32 | ||||||||||||
26 | Test the auxiliary air temperature door control circuit of the auxiliary air temperature actuator from the rear auxiliary HVAC control assembly to the auxiliary HVAC control processor for an open, high resistance, short to ground, and short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 37 | Go to Step 31 | ||||||||||||
27 | Test the auxiliary blower motor switch control circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 37 | Go to Step 31 | ||||||||||||
28 | Test the ignition 3 voltage circuit of the rear auxiliary HVAC control assembly for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 37 | Go to Step 31 | ||||||||||||
29 | Inspect for poor connections at the harness connector of the auxiliary air temperature actuator. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 37 | Go to Step 33 | ||||||||||||
30 | Inspect for poor connections at the harness connector of the front auxiliary HVAC control assembly. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 37 | Go to Step 34 | ||||||||||||
31 | Inspect for poor connections at the harness connector of the rear auxiliary HVAC control assembly. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 37 | Go to Step 35 | ||||||||||||
32 | Inspect for poor connections at the harness connector of the auxiliary HVAC control processor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 37 | Go to Step 36 | ||||||||||||
33 | Replace the auxiliary air temperature actuator. Refer to Auxiliary Temperature Valve Actuator Replacement . Did you complete the replacement? | -- | Go to Step 37 | -- | ||||||||||||
34 | Replace the front auxiliary HVAC control assembly. Refer to Auxiliary Heater and Air Conditioning Control Replacement - Front . Did you complete the replacement? | -- | Go to Step 37 | -- | ||||||||||||
35 | Replace the rear auxiliary HVAC control assembly. Refer to Auxiliary Heater and Air Conditioning Control Replacement - Rear . Did you complete the replacement? | -- | Go to Step 37 | -- | ||||||||||||
36 | Replace the auxiliary HVAC control processor. Refer to Auxiliary HVAC Control Processor Replacement . Did you complete the replacement? | -- | Go to Step 37 | -- | ||||||||||||
37 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 2 |
The numbers below refer to the step numbers on the diagnostic table.
This step checks for proper cooling system operation.
The voltage will vary between 0-12 volts during normal operation. The front auxiliary HVAC control assembly connector must be connected during this step. This checks for proper operation of the air temperature actuator door control circuit and the front auxiliary HVAC control assembly.
Step | Action | Value(s) | Yes | No | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: HVAC Schematics Connector End View Reference: HVAC Connector End Views DEFINITION: The air temperature cannot be adjusted from one or both auxiliary controls or the auxiliary cooling is insufficient. | ||||||||||||||||
1 | Did you review the HVAC operation and perform the necessary inspections? | -- | Go to Step 2 | |||||||||||||
2 |
Does the auxiliary blower motor operate in any of the speed positions? | -- | Go to Step 3 | |||||||||||||
3 | Does the auxiliary blower motor operate correctly for each speed position? | -- | Go to Step 4 | |||||||||||||
Inspect the cooling system for the following conditions:
Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 5 | |||||||||||||
5 |
Does the A/C compressor operate? | -- | Go to Step 6 | |||||||||||||
6 |
Does the auxiliary air temperature actuator drive shaft rotate at all? | -- | Go to Step 7 | Go to Step 8 | ||||||||||||
7 | Inspect the auxiliary air temperature door and the auxiliary air temperature actuator for the following conditions:
Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 8 | ||||||||||||
8 | Test the ignition 3 voltage circuit of the auxiliary air temperature actuator for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 9 | ||||||||||||
9 | Test the ground circuit of the auxiliary air temperature actuator for an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 10 | ||||||||||||
10 | Test the auxiliary air temperature door control circuit of the auxiliary air temperature actuator for an open, high resistance, short to ground, or short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 11 | ||||||||||||
Important:: The front auxiliary HVAC control assembly connector must be connected to correctly perform this test.
Does the voltage measure within the specified values with a smooth transition between COLD and HOT? | 0-12 V | Go to Step 14 | Go to Step 12 | |||||||||||||
12 | Inspect for poor connections at the harness connector of the auxiliary air temperature actuator. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 13 | ||||||||||||
13 | Inspect the auxiliary air temperature actuator, door, and any attaching linkage for binding or a condition that prevents drive shaft rotation. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 15 | ||||||||||||
14 | Inspect for poor connections at the harness connector of the front auxiliary HVAC control assembly. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 16 | ||||||||||||
15 | Replace the auxiliary air temperature actuator. Refer to Auxiliary Temperature Valve Actuator Replacement . Did you complete the replacement? | -- | Go to Step 17 | -- | ||||||||||||
16 | Replace the front auxiliary HVAC control assembly. Refer to Auxiliary Heater and Air Conditioning Control Replacement - Front . Did you complete the replacement? | -- | Go to Step 17 | -- | ||||||||||||
17 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 2 |
The number below refers to the step number on the diagnostic table.
Step | Action | Value(s) | Yes | No | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: HVAC Schematics Connector End View Reference: HVAC Connector End Views DEFINITION: The air temperature can not be adjusted from one or both auxiliary controls or auxiliary cooling is insufficient. | ||||||||||||||||
1 | Did you review the HVAC operation and perform the necessary inspections? | -- | Go to Step 2 | |||||||||||||
2 |
Does the blower motor operate in any of the speed positions? | -- | Go to Step 3 | Go to Blower Motor Inoperative | ||||||||||||
3 | Does blower motor operate correctly for each speed position? | -- | Go to Step 4 | Go to Blower Motor Malfunction | ||||||||||||
Inspect the cooling system for the following conditions:
Did you find and correct the condition? | -- | Go to Step 5 | Go to Too Cold in Vehicle | |||||||||||||
5 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 2 |