A010

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

The outside air temperature sensor is a thermistor that controls the signal voltage to the ACP. The ACP applies a voltage on CKT 735 to the sensor. When the sensor is cold its resistance is high, therefore the ACP will see a high signal voltage at pin 'D8'. 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'.

FAILURE CONDITION(S)

The signal voltages indicates less than -39°C (open circuit) or equal to 53°C (short circuit).

ACTION TAKEN

1. Display '--', on the Instrument Panel Cluster (IPC) temperature display.

2. A substitute temp reading will be implemented to allow operation of the climate control system (AD26 will display the actual sensor reading).

NOTES ON FAULT TREE

1. ACP data value AD26 displays outside temp. The valid operating range is from -38°C to 52°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. Grounding the connector at the ACP will determine if the open is in the ground circuit or at the ACP connection/ACP internal.

Note values of AD25, AD26, AD27, and AD28. If all read near -40 repair open CKT 736 between ACP and C2O1 'X'. If AD25 and AD26 read near -40 repair open CKT 736 between C201 'X' and S219. If only AD26 reads near -40 repair open CKT 736 between 5219 and OAT.

NOTES ON INTERMITTENTS

If the ambient temperature drops below approximately -38°C, this code should be ignored.

If an intermittent code A010 is being set, Select ACP Snapshot Data for Code A010 and note value of AD26. A reaing of approx -40 indicates an intermittent open, a reading of 53 indicates an intermittent short.

Manipulate the related wiring while observing ACP data AD26. If the failure is induce the reading will jump outside its normal range.

If the value displayed by AD26 is not reasonably close to the actual temperature of the air at the sensor, check for poor terminal contact, obstructed sensor, or defective sensor.