Schematic Reference HVAC AIR Delivery/Temperature Control Schematics

Actuators

1

Did you perform the Air Delivery and Temperature Control Check?

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Go to Step 2

Go to Air Delivery and Temperature Control Check

1. Turn OFF the ignition.
2. Disconnect the HTR/DEF/AC door motor.
3. Turn ON the ignition, with the engine OFF.
4. Measure the voltage from the ignition positive voltage circuit of the HTR/DEF/AC door motor to a good ground.

Does the voltage measure near the specified value?

B+

Go to Step 3

Go to Step 4

1. Turn OFF the ignition.
2. Disconnect the heater and A/C programmer.
3. Test the control circuit of the HTR/DEF/AC door motor for a short to ground, a short to voltage, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 13

Go to Step 5

Test the ignition positive voltage circuit of the HTR/DEF/AC door motor for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 13

Go to Step 7

1. Turn OFF the ignition.
2. Connect the heater and A/C programmer.
3. Connect the HTR/DEF/AC door motor.
4. Turn ON the ignition, with the engine OFF.
5. With a scan tool, observe the HTR/DEF/AC Dr Actual data parameter in the Heating and Air Conditioning HVAC Door Positions data list.
6. Connect a 3 amp fused jumper wire between the control circuit of the HTR/DEF/AC door motor and battery voltage (drives the motor to AC).
7. Connect the control circuit of the HTR/DEF/AC door motor to chassis ground (drives the motor to DEF).

Does the drive shaft of the HTR/DEF/AC door motor rotate and do the counts change?

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Go to Step 6

Go to Step 10

1. Measure the voltage from the control circuit of the HTR/DEF/AC door motor to a good ground.
2. With a scan tool, command the HTR/DEF/AC Dr from Defrost to A/C.

Does the voltage measure near the specified value when airflow moves toward AC, near the specified value when airflow moves toward DEF, and near the specified value when stationary?

5 V toward A/C

0 V toward DEF

2.5 V stationary

Go to Step 7

Go to Step 9

1. Turn OFF the ignition.
2. Inspect the HTR/DEF/AC door for a condition preventing full travel or allowing excessive travel of the door.

Did you find and correct the condition?

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Go to Step 13

Go to Step 8

Replace the HVAC module. Refer to HVAC Module Assembly Replacement in Heating and Ventilation.

Did you complete the replacement?

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Go to Step 13

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Inspect for poor connections at the harness connector of the heater and A/C programmer. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 13

Go to Step 11

Inspect for poor connections at the harness connector of the HTR/DEF/AC door motor . Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 13

Go to Step 12

Replace the heater and A/C programmer. Refer to Programmer Replacement .

Did you complete the replacement?

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Go to Step 13

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Replace the HTR/DEF/AC door motor. Refer to Mode Actuator Replacement .

Did you complete the replacement?

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Go to Step 13

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Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 2