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Home >> Mazda >> 2017 >> CX-5 Grand Select, FWD >> Repair and Diagnosis >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> Symptom Troubleshooting - Auto A/C >> Insufficient Air (Or No Air) Blown From Vents [Full-Auto Air Conditioner] >> Diagnostic Procedure

Diagnostic Procedure

DIAGNOSTIC PROCEDURE DESCRIPTION

Step Inspection Action
1 INSPECT FUSE 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.
2* INSPECT TO SEE WHETHER MALFUNCTION (OPEN CIRCUIT) IS IN B+ SIGNAL WIRING HARNESS (BETWEEN FUSE BLOCK AND CLIMATE CONTROL UNIT) OR ELSEWHERE 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 fuse block 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.
3* INSPECT TO SEE WHETHER MALFUNCTION IS IN A/C UNIT OR AIRFLOW MODE ACTUATOR Yes Go to Step 21.
No Go to the next step.
4* INSPECT TO SEE WHETHER MALFUNCTION IS IN POSITION SENSOR OR ELSEWHERE
  • Measure voltage at the following terminals (wiring harness-side) when temperature setting to MAX HOT and MAX COLD.
    • Climate control unit terminal 2K
      • Climate control unit terminal 2I
  • Are voltages normal?
 Yes Go to Step 7.
No Go to the next step.
5* INSPECT TO SEE WHETHER MALFUNCTION (SHORT TO POWER SUPPLY OR GROUND) IS IN POSITION SENSOR POWER SUPPLY OR ELSEWHERE
  • Measure voltage at the following terminal (wiring harness-side).
    • Climate control unit terminal 1C
  • 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.
6* 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).
    • Climate control unit terminal 1Q
  • Is voltage below 1.0 V?
 Yes Refer to wiring diagram and inspect for open circuit following.
  • Between climate control unit terminal 1C and junction point to actuators/sensors (position sensor power supply).
  • Between climate control unit terminal 1Q 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.
7* INSPECT TO SEE WHETHER MALFUNCTION (SHORT TO POWER SUPPLY) IS IN WIRING HARNESS (AIRFLOW MODE POSITION SIGNAL) OR ELSEWHERE
  • Is voltage B+, at Step 3?
 Yes Refer to the wiring diagram and verify whether or not there is a common connector between climate control unit terminal and airflow mode 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.
8 INSPECT CLIMATE CONTROL UNIT CONNECTOR CONNECTION CONDITION Yes Go to the next step.
No Reconnect the climate control unit connector properly.
Go to Step 24.
9 INSPECT CLIMATE CONTROL UNIT CONNECTOR TERMINAL CONDITION Yes Go to the next step.
No Repair/replace the connector or terminal.
Go to Step 24.
10 INSPECT AIRFLOW MODE ACTUATOR CONNECTOR CONNECTION CONDITION Yes Go to the next step.
No Reconnect the airflow mode actuator connector properly.
Go to Step 24.
11 INSPECT AIRFLOW MODE ACTUATOR CONNECTOR TERMINAL CONDITION Yes Go to the next step.
No Repair/replace the connector or terminal.
Go to Step 24.
12* INSPECT TO SEE WHETHER MALFUNCTION (LACK OF CONTINUITY) IS IN WIRING HARNESS (AIRFLOW MODE POSITION SIGNAL) OR ELSEWHERE
  • Inspect for continuity between the following terminals (wiring harness-side):
    • Climate control unit terminal 1B - airflow mode actuator terminal C
  • 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 airflow mode 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.
13* INSPECT TO SEE WHETHER MALFUNCTION (SHORT TO GROUND) IS IN WIRING HARNESS (AIRFLOW MODE POSITION SIGNAL) OR ELSEWHERE
  • Inspect for continuity between the following terminal (wiring harness-side) and body ground:
    • Climate control unit terminal 1B
  • 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 airflow mode 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.
14* INSPECT TO SEE WHETHER MALFUNCTION (OPEN CIRCUIT) IS IN POSITION SENSOR POWER SUPPLY OR ELSEWHERE
  • Inspect for continuity between the following terminal (wiring harness-side) and junction point to other actuators/sensors (position sensor power supply).
    • Airflow mode actuator terminal B
  • 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 airflow mode 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.
15* INSPECT TO SEE WHETHER MALFUNCTION (OPEN CIRCUIT) IS IN POSITION SENSOR GROUND OR ELSEWHERE
  • Inspect for continuity between the following terminal (wiring harness-side) and junction point to other actuators/sensors (position sensor ground).
    • Airflow mode actuator terminal A
  • 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 airflow mode 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 IS IN AIRFLOW MODE ACTUATOR OR WIRING HARNESS (BETWEEN CLIMATE CONTROL UNIT AND AIRFLOW MODE ACTUATOR) Yes Go to Step 20.
No Go to the next step.
17* INSPECT TO SEE WHETHER MALFUNCTION IS IN WIRING HARNESS (LACK OF CONTINUITY BETWEEN CLIMATE CONTROL UNIT AND AIRFLOW MODE ACTUATOR) OR ELSEWHERE 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 airflow mode 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.
18* INSPECT TO SEE WHETHER MALFUNCTION IS IN WIRING HARNESS (SHORT TO B+ BETWEEN CLIMATE CONTROL UNIT AND AIRFLOW MODE ACTUATOR) OR ELSEWHERE
  • Connect the negative battery terminal.

    (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .)

  • Switch the ignition ON (engine off or on).
  • Measure voltage at the following terminals (wiring harness-side).
    • Climate control unit terminal 2B (DEFROSTER mode motor drive signal)
      • Climate control unit terminal 2D (VENT mode 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 airflow mode 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.
19* INSPECT TO SEE WHETHER MALFUNCTION IS IN WIRING HARNESS (SHORT TO GROUND BETWEEN CLIMATE CONTROL UNIT AND AIRFLOW MODE ACTUATOR) OR ELSEWHERE
  • Switch the ignition off.
  • Inspect for continuity between the following terminals (wiring harness-side) and body ground:
    • Climate control unit terminal 2B (DEFROSTER mode motor drive signal)
      • Climate control unit terminal 2D (VENT mode 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 airflow mode 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.
20 INSPECT AIRFLOW MODE ACTUATOR Yes Replace the climate control unit.
(See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER] .)
Go to Step 24.
No Replace the airflow mode actuator.
(See AIRFLOW MODE ACTUATOR REMOVAL [FULL-AUTO AIR CONDITIONER] .)
(See AIRFLOW MODE ACTUATOR INSTALLATION [FULL-AUTO AIR CONDITIONER] .)
Then go to Step 24.
21 INSPECT AIRFLOW MODE LINK SET Yes Go to the next step.
No Apply grease to link.
If any links are damaged, replace malfunctioning part.
(See A/C UNIT DISASSEMBLY/ASSEMBLY .)
Then go to Step 24.
22 INSPECT AIRFLOW MODE DOOR
  • Inspect airflow mode door. (See A/C UNIT DISASSEMBLY/ASSEMBLY .)
    • Is door free of obstructions, cracks and damage?
      • Are door securely and properly installed?
  • Are the above items normal?
 Yes Go to the next step.
No Remove the obstruction, or install door in proper position.
If any doors are cracked or damaged, replace them.
Then go to Step 24.
(See A/C UNIT DISASSEMBLY/ASSEMBLY .)
23 VERIFY DUCT INSTALLATION CONDITION Yes Inspect ducts for restriction, deformity, and air leakage, then go to the next step.
No Install the incorrectly installed ducts properly, then go to the next step.
(See DASHBOARD DISASSEMBLY/ASSEMBLY .)
(See FRONT HEAT DUCT REMOVAL/INSTALLATION .)
(See REAR VENT DUCT REMOVAL/INSTALLATION .)
(See REAR HEAT DUCT REMOVAL/INSTALLATION .)
24 VERIFY THAT MALFUNCTION SYMPTOM DOES NOT RECUR AFTER REPAIR
  • Is air discharged from vent?
 Yes Troubleshooting completed.
Explain repairs to customer.
No Recheck malfunction symptoms, then repeat from Step 1 if the malfunction recurs.
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