NO TEMPERATURE CONTROL WITH CLIMATE CONTROL UNIT [FULL-AUTO AIR CONDITIONER]
id0703c1700600
DESCRIPTION
|
• Temperature does not change when operating temperature control dial
• Malfunction in A/C unit and/or climate control unit air mix system
• Malfunction in driver and/or passenger side air mix actuator or related wiring harness
|
POSSIBLE CAUSE
|
• ROOM 15 A fuse malfunction
• Open or short circuit in wiring harness between fuse block and climate control unit
• Open or short circuit in wiring harness between climate control unit and each actuator / sensor
• Open or short circuit in wiring harness between climate control unit and air mix actuator position sensor
• Climate control unit connector malfunction or poor connection
• Air mix actuator connector malfunction or poor connection
• Air mix actuator malfunction
• Air mix link malfunction
• Air mix door malfunction
• Climate control unit malfunction
• Heater hose malfunction
|
Diagnostic Procedure
Step |
Inspection |
Action |
|
---|---|---|---|
1
|
INSPECT COOLANT TEMPERATURE
• Is the coolant sufficiently warmed up?
|
Yes
|
Go to the next step.
|
No
|
Warm up the engine, then go to Step 24.
|
||
2*
|
INSPECT FUSE
• Switch the ignition off.
• Disconnect the negative battery cable.
• Remove the ROOM 15 A fuse.
• Is the fuse normal?
|
Yes
|
Go to the next step.
|
No
|
If the fuse is blown:
• Refer to the wiring diagram and verify whether or not there is a common connector between ROOM 15 A fuse and climate control unit terminal.
If there is a common connector:
If there is no common connector:
• Replace the fuse.
If the fuse is damaged:
• Replace the fuse.
Then go to Step 24.
|
||
3*
|
INSPECT TO SEE WHETHER MALFUNCTION (OPEN CIRCUIT) IS IN B+ SIGNAL WIRING HARNESS (BETWEEN FUSE BLOCK AND CLIMATE CONTROL UNIT) OR ELSEWHERE
• Disconnect the climate control unit connector.
• Connect the negative battery cable.
• Switch the ignition ON (engine off or on).
• Measure voltage at the following terminal (wiring harness-side).
With dual type climate control unit:
With single type climate control unit:
• Is the voltage B+?
|
Yes
|
Go to the next step.
|
No
|
Refer to the wiring diagram and verify whether or not there is a common connector between fuse block 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, and the common wiring harness for an open circuit.
• Repair or replace the malfunctioning part.
If there is no common connector:
• Repair or replace the wiring harness which has an open circuit.
Go to Step 24.
|
||
4*
|
INSPECT TO SEE WHETHER MALFUNCTION IS IN A/C UNIT OR AIR MIX ACTUATOR
• Switch the ignition off.
• Disconnect the negative battery cable.
• Connect the climate control unit connector.
• Connect the negative battery cable.
• Switch the ignition ON (engine off or on).
• Measure and record the voltage at the following terminals (wiring harness-side) when temperature setting to MAX HOT and MAX COLD.
With dual type climate control unit:
With single type climate control unit:
• Are voltages normal?
|
Yes
|
Go to Step 22.
|
No
|
Go to the next step.
|
||
5*
|
INSPECT TO SEE WHETHER MALFUNCTION IS IN POSITION SENSOR OR ELSEWHERE
• Measure voltage at the following terminal (wiring harness-side) when airflow mode at VENT and DEFROSTER.
With dual type climate control unit:
With single type climate control unit:
• Is voltage normal?
|
Yes
|
Go to Step 8.
|
No
|
Go to the next step.
|
||
6*
|
INSPECT TO SEE WHETHER MALFUNCTION (SHORT TO BATTERY POWER OR GROUND) IS IN POSITION SENSOR POWER SUPPLY OR ELSEWHERE
• Measure voltage at the following terminal (wiring harness-side).
With dual type climate control unit:
With single type climate control unit:
• Is voltage approx. 5 V?
|
Yes
|
Go to the next step.
|
No
|
Refer to the wiring diagram and verify whether or not there is a common connector between climate control unit terminal and each actuator / sensor 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, and the common wiring harness.
• Repair or replace the malfunctioning part.
If there is no common connector:
• Repair or replace the wiring harness.
Go to Step 24.
|
||
7*
|
INSPECT TO SEE WHETHER MALFUNCTION (SHORT TO POWER SUPPLY) IS IN POSITION SENSOR GROUND OR ELSEWHERE
• Measure voltage at the following terminal (wiring harness-side).
With dual type climate control unit:
With single type climate control unit:
• Is the voltage below 1.0 V?
|
Yes
|
Refer to wiring diagram and inspect for open circuit following.
With dual type climate control unit:
• Between climate control unit terminal 1N and junction point to actuators / sensors (position sensor power supply).
• Between climate control unit terminal 1J and junction point to actuators / sensors (position sensor ground).
With single type climate control unit:
• Between climate control unit terminal H and junction point to actuators / sensors (position sensor power supply).
• Between climate control unit terminal E and junction point to actuators / sensors (position sensor ground).
Repair or replace the malfunctioning part or wiring harness.
Go to Step 24.
|
No
|
Refer to the wiring diagram and verify whether or not there is a common connector between climate control unit terminal and each actuator / sensor 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, and the common wiring harness.
• Repair or replace the malfunctioning part.
If there is no common connector:
• Repair or replace the wiring harness.
Go to Step 24.
|
||
8
|
INSPECT TO SEE WHETHER MALFUNCTION (SHORT TO POWER SUPPLY) IS IN WIRING HARNESS (AIR MIX POSITION SIGNAL) OR ELSEWHERE
• Is the voltage B+, at Step 4?
|
Yes
|
Refer to the wiring diagram and verify whether or not there is a common connector between climate control unit terminal and air mix actuator 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, and the common wiring harness for a short to power supply.
• Repair or replace the malfunctioning part.
If there is no common connector:
• Repair or replace the wiring harness which has a short to power supply.
Go to Step 24.
|
No
|
Go to the next step.
|
||
9
|
INSPECT CLIMATE CONTROL UNIT CONNECTOR CONNECTION CONDITION
• Switch the ignition off.
• Disconnect the negative battery cable.
• Inspect the climate control unit connector engagement and connection condition.
• Is the connector normal?
|
Yes
|
Go to the next step.
|
No
|
Reconnect the climate control unit connector properly.
Go to Step 24.
|
||
10
|
INSPECT CLIMATE CONTROL UNIT CONNECTOR TERMINAL CONDITION
• Disconnect the climate control unit connector.
• Inspect the connector and terminals (corrosion, damage, pin disconnection).
• Are the connector and terminals normal?
|
Yes
|
Go to the next step.
|
No
|
Repair/replace the connector or terminal.
Go to Step 24.
|
||
11
|
INSPECT AIR MIX ACTUATOR CONNECTOR CONNECTION CONDITION
• Inspect the air mix actuator connector engagement and connection condition.
• Is the connector normal?
|
Yes
|
Go to the next step.
|
No
|
Reconnect the air mix actuator connector properly.
Go to Step 24.
|
||
12
|
INSPECT AIR MIX ACTUATOR CONNECTOR TERMINAL CONDITION
• Disconnect the air mix actuator connector.
• Inspect the connector and terminals (corrosion, damage, pin disconnection).
• Are the connector and terminals normal?
|
Yes
|
Go to the next step.
|
No
|
Repair/replace the connector or terminal.
Go to Step 24.
|
||
13*
|
INSPECT TO SEE WHETHER MALFUNCTION (LACK OF CONTINUITY) IS IN WIRING HARNESS (AIR MIX POSITION SIGNAL) OR ELSEWHERE
• Inspect continuity between the following terminals (wiring harness-side):
With dual type climate control unit:
With single type climate control unit:
• Is there continuity?
|
Yes
|
Go to the next step.
|
No
|
Refer to the wiring diagram and verify whether or not there is a common connector between climate control unit terminal and air mix actuator 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, and the common wiring harness.
• Repair or replace the malfunctioning part.
If there is no common connector:
• Repair or replace the wiring harness.
Go to Step 24.
|
||
14*
|
INSPECT TO SEE WHETHER MALFUNCTION (SHORT TO GROUND) IS IN WIRING HARNESS (AIR MIX POSITION SIGNAL) OR ELSEWHERE
• Inspect for continuity between the following terminals (wiring harness-side) and body ground:
With dual type climate control unit:
With single type climate control unit:
• Is there continuity?
|
Yes
|
Refer to the wiring diagram and verify whether or not there is a common connector between climate control unit terminal and each side air mix actuator 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, and the common wiring harness.
• Repair or replace the malfunctioning part.
If there is no common connector:
• Repair or replace the wiring harness.
Go to Step 24.
|
No
|
Go to the next step.
|
||
15*
|
INSPECT TO SEE WHETHER MALFUNCTION (OPEN CIRCUIT) IS IN POSITION SENSOR POWER SUPPLY OR ELSEWHERE
• Inspect for continuity between the following terminals (wiring harness-side) and junction point to other actuators / sensors (position sensor power supply).
With dual type climate control unit (L.H.D.):
With dual type climate control unit (R.H.D.):
With single type climate control unit (L.H.D.):
With single type climate control unit (R.H.D.):
• Is there continuity?
|
Yes
|
Go to the next step.
|
No
|
Refer to the wiring diagram and verify whether or not there is a common connector between air mix actuator terminal and junction point to other actuators / sensor 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, and the common wiring harness for an open circuit.
• Repair or replace the malfunctioning part.
If there is no common connector:
• Repair or replace the wiring harness which has an open circuit.
Go to Step 24.
|
||
16*
|
INSPECT TO SEE WHETHER MALFUNCTION (OPEN CIRCUIT) IS IN POSITION SENSOR GROUND OR ELSEWHERE
• Inspect for continuity between the following terminals (wiring harness-side) and junction point to other actuators / sensors (position sensor ground).
With dual type climate control unit (L.H.D.):
With dual type climate control unit (R.H.D.):
With single type climate control unit (L.H.D.):
With single type climate control unit (R.H.D.):
• Is there continuity?
|
Yes
|
Go to the next step.
|
No
|
Refer to the wiring diagram and verify whether or not there is a common connector between air mix actuator terminal and junction point to other actuators / sensor 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, and the common wiring harness for an open circuit.
• Repair or replace the malfunctioning part.
If there is no common connector:
• Repair or replace the wiring harness which has an open circuit.
Go to Step 24.
|
||
17*
|
INSPECT TO SEE WHETHER MALFUNCTION IS IN AIR MIX ACTUATOR OR WIRING HARNESS (LACK OF CONTINUITY BETWEEN CLIMATE CONTROL UNIT AND AIR MIX ACTUATOR)
• Connect the climate control unit connector.
• Connect the negative battery cable.
• Switch the ignition ON (engine off or on).
• Measure voltage at the following terminals (wiring harness-side).
With dual type climate control unit (L.H.D.):
With dual type climate control unit (R.H.D.):
With single type climate control unit (L.H.D.):
With single type climate control unit (R.H.D.):
• Are voltages normal?
|
Yes
|
Go to Step 21.
|
No
|
Go to the next step.
|
||
18*
|
INSPECT TO SEE WHETHER MALFUNCTION IS IN WIRING HARNESS (LACK OF CONTINUITY OR OPEN BETWEEN CLIMATE CONTROL UNIT AND AIR MIX ACTUATOR) OR ELSEWHERE
• Switch the ignition off.
• Disconnect the negative battery cable.
• Disconnect the climate control unit connector.
• Inspect for continuity between the following terminals (wiring harness-side).
With dual type climate control unit (L.H.D.):
With dual type climate control unit (R.H.D.):
With single type climate control unit (L.H.D.):
With single type climate control unit (R.H.D.):
• Is there continuity?
|
Yes
|
Go to the next step.
|
No
|
Refer to the wiring diagram and verify whether or not there is a common connector between climate control unit terminal and air mix actuator 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, and the common wiring harness.
• Repair or replace the malfunctioning part.
If there is no common connector:
• Repair or replace the wiring harness.
Go to Step 24.
|
||
19*
|
INSPECT TO SEE WHETHER MALFUNCTION IS IN WIRING HARNESS (SHORT TO B+ BETWEEN CLIMATE CONTROL UNIT AND AIR MIX ACTUATOR) OR ELSEWHERE
• Climate control unit and air mix actuator connectors are disconnected.
• Connect the negative battery cable.
• Switch the ignition ON (engine off or on).
• Measure voltage at the following terminals (wiring harness-side).
With dual type climate control unit (L.H.D.):
With dual type climate control unit (R.H.D.):
With single type climate control unit:
• Are voltages approx. 0 V?
|
Yes
|
Go to the next step.
|
No
|
Refer to the wiring diagram and verify whether or not there is a common connector between climate control unit terminal and air mix actuator 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, and the common wiring harness for a short to power supply.
• Repair or replace the malfunctioning part.
If there is no common connector:
• Repair or replace the wiring harness which has a short to power supply.
Go to Step 24.
|
||
20*
|
INSPECT TO SEE WHETHER MALFUNCTION IS IN WIRING HARNESS (SHORT TO GROUND BETWEEN CLIMATE CONTROL UNIT AND AIR MIX ACTUATOR) OR ELSEWHERE
• Switch the ignition off.
• Climate control unit and air mix actuator connectors disconnected.
• Inspect for continuity between the following terminals (wiring harness-side) and body ground.
With dual type climate control unit (L.H.D.):
With dual type climate control unit (R.H.D.):
With single type climate control unit:
• Is there continuity?
|
Yes
|
Refer to the wiring diagram and verify whether or not there is a common connector between climate control unit terminal and air mix actuator 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, and the common wiring harness for a short to ground.
• Repair or replace the malfunctioning part.
If there is no common connector:
• Repair or replace the wiring harness which has a short to ground.
Go to Step 24.
|
No
|
Go to the next step.
|
||
21
|
INSPECT AIR MIX ACTUATOR
• Inspect the air mix actuator.
• Is air mix actuator normal?
|
Yes
|
Replace the climate control unit.
Go to Step 24.
|
No
|
Replace the suspected side air mix actuator.
Then go to Step 24.
|
||
22
|
INSPECT AIR MIX LINK
• Inspect the air mix links for each-side.
• Are the above items normal?
|
Yes
|
Go to the next step.
|
No
|
Apply grease to links.
If any links are damaged. Replace malfunctioning part.
Then go to Step 24.
|
||
23
|
INSPECT A/C UNIT AND AIR MIX DOOR
• Inspect the A/C unit and each-side air mix door.
• Are the above items normal?
|
Yes
|
Inspect the heater hoses.
• If the heater hoses are not free of damage and cracks, repair or replace the heater hoses.
• If the heater hose connections are loose, install securely in correct position.
Go to the next step.
|
No
|
Remove the obstruction, or install door in proper position.
If any doors are cracked, replace them.
Then go to the next step.
|
||
24
|
VERIFY THAT MALFUNCTION SYMPTOM DOES NOT RECUR AFTER REPAIR
• Does the unit operate at every temperature setting?
|
Yes
|
Troubleshooting completed.
Explain repairs to customer.
|
No
|
Recheck malfunction symptoms, then repeat from Step1 if the malfunction recurs.
|