NO.1 INSUFFICIENT AIR (OR NO AIR) BLOWN FROM VENTS [FULL-AUTO AIR CONDITIONER]
id0703c1800400
1
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Insufficient air (or no air) blown from vents
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DESCRIPTION
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• Problem with each vent and/or duct.
• Airflow mode does not change.
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POSSIBLE CAUSE
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• Climate control unit (B+ signal) system malfunction
• Climate control unit (VENT, DEFROSTER signal) system malfunction
• Malfunction in airflow mode actuator
• Malfunction in VENT mode system
• Malfunction in HEAT mode system
• Malfunction in DEFROSTER mode system
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Diagnostic procedure
STEP |
INSPECTION |
ACTION |
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1*
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INSPECT CLIMATE CONTROL UNIT POWER SUPPLY FUSE FOR B+ SIGNAL
• Is the climate control unit power supply fuse for B+ signal normal?
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Yes
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Go to the next step.
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No
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Inspect for short to GND in blown fuse circuit
Repair or replace as necessary.
Install appropriate amperage fuse.
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2*
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INSPECT TO SEE WHETHER MALFUNCTION (OPEN CIRCUIT) IS IN B+ SIGNUL WIRING HARNESS (BETWEEN FUSE BLOCK AND CLIMATE CONTROL UNIT) OR ELSEWHERE
• Disconnect the climate control unit connector (24-pin).
• Switch the ignition to ON.
• Measure the voltage at climate control unit harness-side connector (24-pin) terminal 1E (B+ signal).
• Is the voltage approx. 12V?
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Yes
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Go to the next step.
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No
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Repair wiring harness between fuse block and climate control unit, then go to Step 20.
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3*
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INSPECT TO SEE WHETHER MALFUNCTION (LACK OF CONTINUITY) IS IN WIRING HARNESS (BETWEEN CLIMATE CONTROL UNIT AND GND) OR ELSE ELSEWHERE
• Climate control unit connector (24-pin) disconnected.
• Verify that continuity between climate control unit harness-side connector (24-pin) terminal 1D and GND.
• Is there continuity?
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Yes
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Go to the next step
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No
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Repair wiring harness between climate control unit and GND.
Inspect GND point condition.
Then go to Step 20.
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4*
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INSPECT TO SEE WHETHER MALFUNCTION IS IN A/C UNIT OR AIRFLOW MODE ACTUATOR
• Switch the ignition to ON.
• Measure voltage at climate control unit terminal 2B (12-pin) when airflow mode change to VENT and DEFROSTER.
• Is voltage normal?
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Yes
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Go to the next step.
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No
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Go to Step 16.
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5*
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INSPECT TO SEE WHETHER MALFUNCTION IS IN POSITION OR ELSEWHERE
• Switch the ignition to ON.
• Measure voltage at climate control unit terminal 2A and 2C (12-pin) when temperature controls dial at MAX HOT and MAX COLD.
• Are voltages normal?
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Yes
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Go to Step 8.
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No
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Go to the next step.
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6*
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INSPECT TO SEE WHETHER MALFUNCTION (LACK OF CONTINUITY OR SHORT TO BATTERY POWER OR GND) IS IN POTENTIOMETER POWER SUPPLY (CLIMATE CONTROL UNIT TERMINAL 2K) OR ELSEWHERE
• Switch the ignition to ON.
• Measure voltage at climate control unit terminal 2K (12-pin).
• Is voltage approx. 5V?
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Yes
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Go to the next step.
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No
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Repair wiring harness between climate control unit terminal 2K and follows:
• Airflow mode actuator terminal A
• Driver side air mix actuator terminal G (L.H.D.), E (R.H.D.)
• Passenger side air mix actuator terminal E (L.H.D.), G (R.H.D.)
Then go to Step 20.
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7*
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INSPECT TO SE WHETHER MAL FUNCTION (LACK OF CONTINUITY OR OPEN) IS IN POTENTIOMETER GND (CLIMATE CONTROL UNIT TERMINAL 2L) OR ELSEWHERE
• Measure voltage at climate control unit terminal 2L (12-pin)
• Is voltage below 1.0V?
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Yes
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Go to Step 11.
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No
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Repair wiring harness between climate control unit terminal 2L and follows:
• Airflow mode actuator terminal B
• Driver side airflow mode actuator terminal E (L.H.D.), G (R.H.D.)
• Passenger side airflow mode actuator terminal G (L.H.D.), E (R.H.D.)
Then go to Step 20.
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8*
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INSPECT TO SEE WHETHER MALFUNCTION (SHORT TO POWER) IS IN WIRING HARNESS (AIRFLOW MODE POSITION SIGNAL) OR ELSEWHERE
• Is climate control unit terminal 2B voltage approx. 12V, at Step 4?
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Yes
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Repair wiring harness between climate control unit terminal 2B and airflow mode actuator terminal C.
Then go to Step 20.
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No
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Go to the next step.
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9*
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INSPECT TO SEE WHETHER MALFUNCTION (LACK OF CONTINUITY) IS IN WIRING HARNESS (AIRFLOW MODE POSITION SIGNAL) OR ELSEWHERE
• Switch the ignition off.
• Disconnect climate control unit and airflow mode actuator connectors.
• Verify continuity between climate control unit terminal 2B (12-pin) and airflow mode actuator terminal C at harness-side connector.
• Is there continuity?
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Yes
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Go to next step.
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No
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Repair wiring harness between climate control unit terminal 2B and airflow mode actuator terminal C.
Then go to Step 20.
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10*
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INSPECT TO SEE WHETHER MALFUNCTION (SHORT TO GND) IS IN WIRING HARNESS (AIRFLOW MODE POSITION SIGNAL) OR POTENTIOMETER COMMON (POWER SUPPLY OR GND) HARNESS
• Verify continuity between climate control unit harness-side connector terminal 2B (12-pin) and GND.
• Is there continuity?
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Yes
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Repair wiring harness between climate control unit terminal 2B and airflow mode actuator terminal C.
Then go to Step 20.
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No
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Inspection and repair for open circuit following:
• Between airflow mode actuator terminal A and junction point to each air mix actuator (potentiometer power supply).
• Between airflow mode actuator terminal B and junction point to each air mix actuator (potentiometer GND).
Then go to Step 20.
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11*
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INSPECT TO SEE WHETHER MALFUNCTION (LACK OF CONTINUITY) IS IN AIRFLOW MODE ACTUATOR WIRING HARNESS (BETWEEN CLIMATE CONTROL UNIT AND AIRFROW MODE ACTUATOR) OR ELSEWHERE
• Switch the ignition to ON.
• Measure voltage at the following terminals of climate control unit.
• Are voltages okay?
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Yes
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Go to the next step.
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No
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Go to Step 13.
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12*
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INSPECT TO SEE WHETHER MALFUNCTION (LACK OF CONTINUITY) IS IN AIRFROW MODE ACTUATOR OR WIRING HARNESS (BETWEEN CLIMATE CONTROL UNIT AND AIRFROW MODE ACTUATOR)
• Measure voltage at the following terminals of climate control unit.
• Are voltages as shown below?
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Yes
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Go to Step 17.
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No
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Repair wiring harness between climate control unit and airflow mode actuator.
Then go to Step 20.
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13*
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INSPECT TO SEE WHETHER MALFUNCTION IS IN AIRFROW MODE ACTUATOR OR ELSEWHERE
• Disconnect the airflow mode actuator.
• Measure voltage at the following terminals of climate control unit.
• Are voltage okay?
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Yes
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Go to Step 16.
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No
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Go to the next step.
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14*
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INSPECT TO SEE WHETHER MALFUNCTION IS IN WIRING HARNESS (SHORT TO B+ BETWEEN CLIMATE CONTROL UNIT AND AIRFLOW MODE ACTUATOR) OR ELSEWHERE
• Disconnect the climate control unit connector.
• Measure voltage at the following terminal of the climate control unit harness-side connector.
• Are voltages approx. 0V?
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Yes
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Go to the next step.
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No
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Repair wiring between climate control unit and airflow mode actuator.
Then go to the Step 20.
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15*
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INSPECT TO SEE WHETHER MALFUNCTION IS IN WIRING HARNESS (SHORT TO GND BETWEEN CLIMATE CONTROL UNIT AND AIRFLOW MODE ACTUATOR) OR ELSEWHERE
• Switch the ignition to off.
• Verify that continuity at the following harness-side connector terminals between climate control unit and GND.
• Is there continuity?
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Yes
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Repair wiring harness between climate control unit and airflow mode actuator.
Then go to the Step 20.
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No
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Go to the next step.
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16
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INSPECT AIRFLOW MODE ACTUATOR
• Inspect airflow mode actuator.
• Is airflow mode actuator normal?
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Yes
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Go to the next step.
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No
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Replace the airflow mode actuator.
Then go to the Step 20.
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17
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INSPECT AIRFLOW MODE LINK
• Inspect airflow mode links.
• Are above items okay?
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Yes
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Go to the next step.
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No
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Apply grease to links.
If any links are damaged, replace malfunctioning part.
Then go to the Step 20.
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18
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INSPECT TO SEE WHETHER MALFUNCTION IS IN CLIMATE CONTROL UNIT OR AIRFLOW MODE DOOR
• Inspect A/C unit airflow mode door.
• Are above items okay?
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Yes
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Go to the next step.
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No
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Remove the obstruction, or install door in proper position.
If any doors are cracked or damaged, replace them.
Then go to the Step 20.
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19
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VERIFY THAT DUCTS INSTALLATION CONDITION
• Are following ducts installed properly?
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Yes
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Inspect ducts for clogging, deformity, and air leakage, then go to the next step.
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No
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Install the suspected ducts properly, then go to the next step.
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20
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CONFIRM THAT MALFUNCTION SYMPTOM DOES NOT RECUR AFTER REPAIR
• Does air blow out?
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Yes
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Troubleshooting completed.
Explain repairs to customer.
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No
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Recheck malfunction symptoms, then repeat from Step 1 if the malfunction recurs.
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