Chart 5 Improper Temperature Control

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

Given the driver's selected set temperature, the 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.


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 I/P opening or the ground CKT 736 is causing the incorrect reading.

7. Checks to determine if the outside temp. sensor is providing an accurate temperature 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 736 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 736 is causing the incorrect reading.