Air Conditioning System

AIR CONDITIONING SYSTEM: 12: Ambient Temperature Sensor Circuit

DTC 12 - Ambient Temperature Sensor Circuit

DESCRIPTION

This sensor detects the temperature outside the cabin and sends the appropriate signals to the A/C amplifier.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. CHECK ACCESSORY METER
(a) Check that the accessory meter panel display is correct.
Standard:
Display is correct
Result

B -- INSPECT AIR CONDITIONING AMPLIFIER
A -- Continue to next step.
2. INSPECT ACCESSORY METER PANEL

(a) Remove the accessory meter panel with the connector still connected.
(b) Turn the ignition switch to the ON position.
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage:

OK -- INSPECT AIR CONDITIONING AMPLIFIER
NG -- Continue to next step.
3. INSPECT THERMISTOR ASSEMBLY (AMBIENT TEMP. SENSOR)
(a) Remove the thermistor assembly (ambient temp. sensor).

(b) Disconnect the connector from the thermistor assembly (ambient temp. sensor).

NG -- REPLACE THERMISTOR ASSEMBLY (AMBIENT TEMP. SENSOR)
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (THERMISTOR ASSEMBLY - ACCESSORY METER PANEL)
(a) Check for open or short circuit in the harness and the connector between the accessory meter panel and the thermistor assembly (ambient temp. sensor) Electronic Circuit Inspection Procedure.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ACCESSORY METER PANEL
5. INSPECT AIR CONDITIONING AMPLIFIER

(a) Remove the A/C amplifier with the connectors still connected.
(b) Turn the ignition switch to the ON position.
(c) Measure the waveform between terminal TAMIN of the A/C amplifier connector and body ground.
OK:
Pulse generation
Result:

C -- REPLACE AIR CONDITIONING AMPLIFIER
B -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
A -- Continue to next step.
6. CHECK HARNESS AND CONNECTOR (ACCESSORY METER PANEL - A/C AMPLIFIER)
(a) Check for open or short circuit in the harness and the connector between the accessory meter panel and the A/C amplifier Electronic Circuit Inspection Procedure.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ACCESSORY METER PANEL