A011

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

The Hi Side Temperature sensor is a thermistor that controls a signal voltage to the ACE The ACP applies a voltage on CKT 732 to the sensor. When the sensor is cold its resistance is high, therefore the ACP will see a high signal voltage at pin 'D14'. As the sensor warms, its resistance becomes less and the signal voltage is pulled low through the sensor ground, CKT 736. This signal voltage will vary between 5V (open circuit) an 0V (short circuit).

TEST CONDITION(S)

1. Ignition 'ON'.

2. Code A010 not set.

3. Temperature greater than 30°F

FAILURE CONDITION(S)

The signal voltages indicates less than -18°C (open circuit) or greater than 179°C (short circuit) calibrated.

ACTION TAKEN

1. HI Coolant Fan operation when A/C compressor operation possible.

NOTES ON FAULT TREE

1. ACP data value AD27 displays Hi Side temperature. The valid operating range is from -18°C to 179°C.

2. A reading too low indicates an open circuit. Jumpering the harness connector will determine whether the wiring or sensor is the cause of the open.

3. A reading too hi indicates a short circuit. Removing the sensor will determine whether the wiring or sensor is the cause of the short.

4. The open has been determined to be in the wiring. Providing a ground at the jumper will determine if the open is in the ground wiring or the sensing wire.

5. Grounding the connector at the ACP will determine if the open is in the sense circuit or at the ACP connection/ACP internal.

6. Note values of AD25, AD26, AD27, and AD28. If all read near -40 repair open CKT 736 between ACP and C201 'X'. If AD27 and AD28 read near -40 repair open CKT 736 between C201 'X' and S218. If only AD27 reads near -40 repair open CKT 736 between S218 and Hi-Side sensor.

NOTES ON INTERMITTENTS

If an intermittent code A011 is being set, Select ACP Snapshot Data for Code A011 and note value of AD27. A reading of approx -38 indicates an intermittent open, a reading above 179 indicates an intermittent short.

Manipulate the related wiring while observing ACP data AD27. If the failure is induced, the reading will jump outside its normal range.