A040

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

The Air Conditioning Programmer (ACP) applies voltage to a motor that moves the air mix door. A sensor on the motor provides feedback to the ACP. When the ACP commands the mix door to move and the feedback voltage does not change, the ACP sets DTC A040. If the air mix door feedback voltage is near the hot or cold extreme door positions, the ACP will not set DTC A040. Air mix door operation can be monitored through the vehicle diagnostic system.

TEST CONDITION(S)

1. Commanded Mix Door greater than 0%.

2. Commanded Mix Door less than 76%.

FAILURE CONDITION(S)

1. Actual Air Mix Door not within 3% of ACP commanded Air Mix Door Position, after approximately 60 seconds.

ACTION TAKEN

None.

NOTES ON FAULT TREE

Before performing diagnostic, display AS12. While monitoring AD23, command the air mix door to various positions. Without keying OFF, physically inspect the air mix door linkage for any obstructions.

1. Display ACP override AS12, normal range is from 1 to 99. Observe the AD23 (air mix door position sensor feedback value) and compare to AD22 (air mix door commanded position value). Perform the following steps to command the air mix door.

A. Press "OFF", a new test type is selected.

B. Select DATA, and then AD23.

C. Press the "WARMER or COOLER" buttons to command the air mix door to any position.

2. These readings indicate a fault, internal to the ACP, in the air mix door sensor feedback.

3. If the door is not stuck, ensure smooth operation before replacing ACP.

NOTES ON INTERMITTENT CONNECTION
If an intermittent DTC is being set, select ACP Snapshot Data for DTC and note value of ACP data parameter. Manipulate the related wiring while observing ACP data parameter. If a failure is induced, the displayed data parameter value will be outside the sensors normal operating range.