Chart 5 Improper Temperature Control

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

Given the driver's selected set temperature, the Air Conditioning Programmer (ACP) uses the inside air temperature sensor (AD25) to determine if the interior of the vehicle requires heating or cooling to achieve and maintain the selected comfort level. The ACP monitors the outside temperature sensor (AD26), solar sensor (AD32) and the coolant temperature (AD21) to determine the required air mix door position, blower speed and air delivery mode.

NOTE: Verify customer complaint as compared to a comparable vehicle prior to attempting diagnosis.

TEST DESCRIPTION

Numbers below refer to circled numbers on the diagnostic chart.

1. Checks to determine that the heater system has sufficient heating capacity.

2. Checks to determine that the refrigerant system has sufficient cooling capacity.

3. Checks to determine if the solar sensor reacts correctly to a no light condition.

4. Checks to determine if either the solar sensor or the power CKT 590 is causing the incorrect reading.

5. Checks to determine if the solar sensor reacts correctly to a bright light condition.

6. checks to determine if either the solar sensor, its alignment to the Instrument Panel (I/P) opening or the ground CKT 407 is causing the incorrect reading.

7. Checks to determine if the outside temp. sensor is providing an accurate temp. reading.

8. Checks to determine if the power CKT 735 has high resistance or is shorted to ground causing the incorrect reading.

9. Checks to determine if either the outside temp. sensor or CKT 407 is causing the incorrect reading.

10. Checks to determine if there is component or "build" condition which is causing the inside air temp. sensor to have the incorrect reading.

11. Checks to determine if the power CKT 734 has high resistance or shorted to ground causing the incorrect reading.

12. Checks to determine if the inside air temperature sensor, its connectors, alignment within housing or the ground CKT 407 is causing the incorrect reading.

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.