CLIMATE CONTROL UNIT DOES NOT STORE INFORMATION [FULL-AUTO AIR CONDITIONER]

id0703c1005900

DESCRIPTION

•  When ignition is switched ON (engine off or on), climate control unit activated with set temperature at 22 °C {72 °F} while in AUTO

•  Past malfunction code is not stored in climate control unit

POSSIBLE CAUSE

•  Open circuit or short to ground in wiring harness between climate control unit terminal 2A an ROOM 25 A fuse

•  ROOM 25 A fuse blown

•  Climate control unit malfunction

Diagnostic Procedure

• When performing an asterisked (*) troubleshooting inspection, shake the wiring harness and connectors while performing the inspection to discover whether poor contact points are the cause of any intermittent malfunctions. If there is a problem, check to make sure connectors, terminals and wiring harnesses are connected correctly and undamaged.

Step

Inspection

Action

1

INSPECT FUSE

•  Inspect ROOM 25 A fuse

•  Is the fuse normal?

Yes

Go to the next step.

No

Replace the fuse, then go to Step 3.

If the fuse blows immediately after replacement, go to the next step.

2^*

INSPECT CLIMATE CONTROL UNIT +B SIGNAL

•  Measure the voltage at the following terminals:

―  Climate control unit terminal 2A

•  Is the voltage B+?

Yes

Replace the climate control unit, then go to the next step.

(See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.)

No

Refer to the wiring diagram and verify whether or not there is a common connector between ROOM 25 A fuse terminal and climate control unit terminal.

If there is a common connector:

•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection.

•  Repair or replace the malfunctioning part.

If there is no common connector:

•  Repair or replace the wiring harness.

Go to the next step.

3

VERIFY THAT MALFUNCTION SYMPTOM DOES NOT RECUR AFTER REPAIR

•  Does the climate control unit store information normally?

Yes

Troubleshooting completed.

Explain repairs to customer.

No

Recheck malfunction symptoms, then repeat from Step 1 if the malfunction recurs.

DESCRIPTION	• When ignition is switched ON (engine off or on), climate control unit activated with set temperature at 22 °C {72 °F} while in AUTO • Past malfunction code is not stored in climate control unit
POSSIBLE CAUSE	• Open circuit or short to ground in wiring harness between climate control unit terminal 2A an ROOM 25 A fuse • ROOM 25 A fuse blown • Climate control unit malfunction

Step	Inspection		Action
1	INSPECT FUSE • Inspect ROOM 25 A fuse • Is the fuse normal?	Yes	Go to the next step.
1		No	Replace the fuse, then go to Step 3. If the fuse blows immediately after replacement, go to the next step.
2^*	INSPECT CLIMATE CONTROL UNIT +B SIGNAL • Measure the voltage at the following terminals: ― Climate control unit terminal 2A • Is the voltage B+?	Yes	Replace the climate control unit, then go to the next step. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.)
2^*		No	Refer to the wiring diagram and verify whether or not there is a common connector between ROOM 25 A fuse terminal and climate control unit terminal. If there is a common connector: • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection. • Repair or replace the malfunctioning part. If there is no common connector: • Repair or replace the wiring harness. Go to the next step.
3	VERIFY THAT MALFUNCTION SYMPTOM DOES NOT RECUR AFTER REPAIR • Does the climate control unit store information normally?	Yes	Troubleshooting completed. Explain repairs to customer.
3		No	Recheck malfunction symptoms, then repeat from Step 1 if the malfunction recurs.