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

•  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, inspect to make sure connectors, terminals and wiring harnesses are connected correctly and undamaged.

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.
•  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:
―  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.
•  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.
•  Switch the ignition ON (engine off or on).
•  Measure voltage at the following terminal (wiring harness-side).
With dual type climate control unit:
―  Climate control unit terminal 1B
With single type climate control unit:
―  Climate control unit terminal L
•  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.
•  Connect the climate control unit connector.
•  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:
―  Climate control unit terminal 2G
―  Climate control unit terminal 2E
With single type climate control unit:
―  Climate control unit terminal G
•  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:
―  Climate control unit terminal 2A
With single type climate control unit:
―  Climate control unit terminal I
•  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:
―  Climate control unit terminal 1N
With single type climate control unit:
―  Climate control unit terminal H
•  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:
―  Climate control unit terminal 1J
With single type climate control unit:
―  Climate control unit terminal E
•  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.
•  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:
―  Climate control unit terminal 2G—air mix actuator terminal F
―  Climate control unit terminal 2E—air mix actuator terminal F
With single type climate control unit:
―  Climate control unit terminal G—air mix actuator terminal F
•  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:
―  Climate control unit terminal 2G
―  Climate control unit terminal 2E
With single type climate control unit:
―  Climate control unit terminal G
•  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.):
―  Driver-side air mix actuator terminal G
―  Passenger-side air mix actuator terminal E
With dual type climate control unit (R.H.D.):
―  Driver-side air mix actuator terminal E
―  Passenger-side air mix actuator terminal G
With single type climate control unit (L.H.D.):
―  Climate control unit terminal E
With single type climate control unit (R.H.D.):
―  Climate control unit terminal G
•  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.):
―  Driver-side air mix actuator terminal E
―  Passenger-side air mix actuator terminal G
With dual type climate control unit (R.H.D.):
―  Driver-side air mix actuator terminal G
―  Passenger-side air mix actuator terminal E
With single type climate control unit (L.H.D.):
―  Climate control unit terminal G
With single type climate control unit (R.H.D.):
―  Climate control unit terminal E
•  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.
•  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.):
―  Driver-side air mix actuator terminal B (HOT motor drive signal)
―  Driver-side air mix actuator terminal C (COLD motor drive signal)
―  Passenger-side air mix actuator terminal C (HOT motor drive signal)
―  Passenger-side air mix actuator terminal B (COLD motor drive signal)
With dual type climate control unit (R.H.D.):
―  Driver-side air mix actuator terminal C (HOT motor drive signal)
―  Driver-side air mix actuator terminal B (COLD motor drive signal)
―  Passenger-side air mix actuator terminal B (HOT motor drive signal)
―  Passenger-side air mix actuator terminal C (COLD motor drive signal)
With single type climate control unit (L.H.D.):
―  Air mix actuator terminal C (HOT motor drive signal)
―  Air mix actuator terminal B (COLD motor drive signal)
With single type climate control unit (R.H.D.):
―  Air mix actuator terminal B (HOT motor drive signal)
―  Air mix actuator terminal C (COLD motor drive signal)
•  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 climate control unit connector.
•  Inspect for continuity between the following terminals (wiring harness-side).
With dual type climate control unit (L.H.D.):
―  Climate control unit terminal 2D—driver-side air mix actuator terminal B (HOT motor drive signal)
―  Climate control unit terminal 2B—driver-side air mix actuator terminal C (COLD motor drive signal)
―  Climate control unit terminal 2F—passenger-side air mix actuator terminal C (HOT motor drive signal)
―  Climate control unit terminal 2H—passenger-side air mix actuator terminal B (COLD motor drive signal)
With dual type climate control unit (R.H.D.):
―  Climate control unit terminal 2F—driver-side air mix actuator terminal C (HOT motor drive signal)
―  Climate control unit terminal 2H—driver-side air mix actuator terminal B (COLD motor drive signal)
―  Climate control unit terminal 2D—passenger-side air mix actuator terminal B (HOT motor drive signal)
―  Climate control unit terminal 2B—passenger-side air mix actuator terminal C (COLD motor drive signal)
With single type climate control unit (L.H.D.):
―  Climate control unit terminal X—air mix actuator terminal C (HOT motor drive signal)
―  Climate control unit terminal W—air mix actuator terminal B (COLD motor drive signal)
With single type climate control unit (R.H.D.):
―  Climate control unit terminal X—air mix actuator terminal B (HOT motor drive signal)
―  Climate control unit terminal W—air mix actuator terminal C (COLD motor drive signal)
•  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.
•  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.):
―  Climate control unit terminal 2D (driver-side HOT motor drive signal)
―  Climate control unit terminal 2B (driver-side COLD motor drive signal)
―  Climate control unit terminal 2F (passenger-side HOT motor drive signal)
―  Climate control unit terminal 2H (passenger-side COLD motor drive signal)
With dual type climate control unit (R.H.D.):
―  Climate control unit terminal 2F (driver-side HOT motor drive signal)
―  Climate control unit terminal 2H (driver-side COLD motor drive signal)
―  Climate control unit terminal 2D (passenger-side HOT motor drive signal)
―  Climate control unit terminal 2B (passenger-side COLD motor drive signal)
With single type climate control unit:
―  Climate control unit terminal X (HOT motor drive signal)
―  Climate control unit terminal W (COLD motor drive signal)
•  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.):
―  Climate control unit terminal 2D (driver-side HOT motor drive signal)
―  Climate control unit terminal 2B (driver-side COLD motor drive signal)
―  Climate control unit terminal 2F (passenger-side HOT motor drive signal)
―  Climate control unit terminal 2H (passenger-side COLD motor drive signal)
With dual type climate control unit (R.H.D.):
―  Climate control unit terminal 2F (driver-side HOT motor drive signal)
―  Climate control unit terminal 2H (driver-side COLD motor drive signal)
―  Climate control unit terminal 2D (passenger-side HOT motor drive signal)
―  Climate control unit terminal 2B (passenger-side COLD motor drive signal)
With single type climate control unit:
―  Climate control unit terminal X (HOT motor drive signal)
―  Climate control unit terminal W (COLD motor drive signal)
•  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.
―  Is grease on link?
―  Are links securely and properly installed?
―  Are links free of obstructions and hindrances?
•  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.
―  Is door free of obstructions and damage?
―  Are doors securely and properly installed?
•  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.