Back-Up Power Source Circuit

AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Automatic Air Conditioning System): Back-up Power Source Circuit
- Back-up Power Source Circuit

DESCRIPTION

This is the back-up power source circuit for the air conditioning amplifier. Power is supplied even when the ignition switch is turned off and is used for functions such as the diagnostic trouble code memory.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT FUSE (ECU-B2)

(a) Remove the ECU-B2 fuse from the engine room No. 2 relay block.

(b) Measure the resistance of the fuse.

Standard resistance:

Below 1 Ohms

NG -- REPLACE FUSE
OK -- Continue to next step.

2. CHECK WIRE HARNESS (AIR CONDITIONING AMPLIFIER - BATTERY)





(a) Disconnect the E37 amplifier connector.

(b) Measure the voltage of the wire harness side connector.

Standard voltage:





NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.

3. CHECK WIRE HARNESS (AIR CONDITIONING AMPLIFIER - BODY GROUND)





(a) Disconnect the E37 amplifier connector.

(b) Measure the resistance of the wire harness side connector.

Standard resistance:





NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR

OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE