DTC B1142:13 [CLIMATE CONTROL UNIT (FULL-AUTO AIR CONDITIONER)] - MAZDA CX-9 TC 2016

DTC B1142:13 [CLIMATE CONTROL UNIT (FULL-AUTO AIR CONDITIONER)]

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Note

• There are two types of front climate control unit, type A and type B.

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With i-stop

System malfunction location	• Rear climate control unit power supply circuit open (IG1)
Detection condition	• Rear climate control unit detects the difference between IG1 signal and IG2 signal
Fail-safe function	Not applicable
Possible cause	• Rear climate control unit connector malfunction • Open circuit in wiring harness between battery positive terminal and rear climate control unit terminal • Short to power supply in wiring harness between front body control module (FBCM) and rear climate control unit terminal • Rear climate control unit malfunction • Front body control module (FBCM) malfunction

Diagnostic procedure

STEP	INSPECTION		ACTION
1	INSPECT IGNITION RELAY (IG1_STAB) FOR MALFUNCTION • Remove the IGNITION relay (IG1_STAB). (See RELAY LOCATION.) • Inspect the IGNITION relay (IG1_STAB). (See RELAY INSPECTION.) • Is the IGNITION relay (IG1_STAB) normal?	Yes	Go to the next step.
1		No	Replace the IGNITION relay (IG1_STAB). (See RELAY LOCATION.) Then go to Step 6.
2	PERFORM FRONT BODY CONTROL MODULE (FBCM) DTC INSPECTION • Perform the front body control module (FBCM) DTC inspection using the M-MDS. (See DTC INSPECTION [FRONT BODY CONTROL MODULE (FBCM)].) • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [FRONT BODY CONTROL MODULE (FBCM)].)
2		No	Go to the next step.
3	VERIFY REAR CLIMATE CONTROL UNIT CONNECTOR CONDITION • Switch the ignition off. • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Disconnect the rear climate control unit connector. (See REAR CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.) • Inspect the connector and terminals (corrosion, damage, pin disconnection). • Are the connector and terminals normal?	Yes	Go to the next step.
3		No	Repair/replace the connector or terminal. After repair procedure, go to Step 6.
4	INSPECT IG2 CIRCUIT (BETWEEN REAR CLIMATE CONTROL UNIT AND FRONT BODY CONTROL MODULE (FBCM)) FOR SHORT TO POWER SUPPLY • Rear climate control unit connector is disconnected. • Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Switch the ignition off. • Measure the voltage at the following terminal (wiring harness-side): ? Rear climate control unit terminal B • Is the voltage 0 V?	Yes	Go to the next step.
4		No	Refer to the wiring diagram and verify whether or not there is a common connector between front body control module (FBCM) terminal and front climate control unit / rear 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 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 6.
5	INSPECT IG1 CIRCUIT (BETWEEN REAR CLIMATE CONTROL UNIT AND IGNITION RELAY (IG1_STAB)) FOR OPEN CIRCUIT • Rear climate control unit connector is disconnected. • Switch the ignition ON (engine off or on). • Measure the voltage at the following terminal (wiring harness-side): ? Rear climate control unit terminal X • Is the voltage B+?	Yes	Go to the next step.
5		No	Refer to the wiring diagram and verify whether or not there is a common connector between battery positive terminal and rear 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 the next step.
6	VERIFY THAT SAME DTC IS NOT OUTPUT AGAIN • Reconnect the disconnected connectors. • Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Clear the DTC from the climate control unit memory using the M-MDS. (See CLEARING DTC [CLIMATE CONTROL UNIT (FULL-AUTO AIR CONDITIONER)].) • Perform the DTC inspection for the climate control unit using the M-MDS. (See DTC DISPLAY [CLIMATE CONTROL UNIT (FULL-AUTO AIR CONDITIONER)].) • Is the same DTC displayed?	Yes	Repeat the inspection from Step 1. • If the malfunction recurs, replace the rear climate control unit. (See REAR CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.) Go to the next step.
6		No	Go to the next step.
7	VERIFY THAT NO OTHER DTCs ARE PRESENT • Verify other DTCs displayed. • Are any other DTCs displayed?	Yes	Repair or replace the malfunctioning part according to the applicable DTC troubleshooting. (See DTC TABLE [CLIMATE CONTROL UNIT (FULL-AUTO AIR CONDITIONER)].)
7		No	DTC troubleshooting completed.

Without i-stop

System malfunction location	• Rear climate control unit power supply circuit open (IG1)
Detection condition	• Rear climate control unit detects the difference between IG1 signal and IG2 signal
Fail-safe function	Not applicable
Possible cause	• Rear climate control unit connector malfunction • Open circuit in wiring harness between battery positive terminal and rear climate control unit terminal • Short to power supply in wiring harness between front body control module (FBCM) and rear climate control unit terminal • Rear climate control unit malfunction • Front body control module (FBCM) malfunction

Diagnostic procedure

STEP	INSPECTION		ACTION
1	PERFORM FRONT BODY CONTROL MODULE (FBCM) DTC INSPECTION • Perform the front body control module (FBCM) DTC inspection using the M-MDS. (See DTC INSPECTION [FRONT BODY CONTROL MODULE (FBCM)].) • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [FRONT BODY CONTROL MODULE (FBCM)].)
1		No	Go to the next step.
2	VERIFY REAR CLIMATE CONTROL UNIT CONNECTOR CONDITION • Switch the ignition off. • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Disconnect the rear climate control unit connector. (See REAR CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.) • Inspect the connector and terminals (corrosion, damage, pin disconnection). • Are the connector and terminals normal?	Yes	Go to the next step.
2		No	Repair/replace the connector or terminal. After repair procedure, go to Step 5.
3	INSPECT IG2 CIRCUIT (BETWEEN REAR CLIMATE CONTROL UNIT AND FRONT BODY CONTROL MODULE (FBCM)) FOR SHORT TO POWER SUPPLY • Rear climate control unit connector is disconnected. • Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Switch the ignition off. • Measure the voltage at the following terminal (wiring harness-side): ? Rear climate control unit terminal B • Is the voltage 0 V?	Yes	Go to the next step.
3		No	Refer to the wiring diagram and verify whether or not there is a common connector between front body control module (FBCM) terminal and front climate control unit / rear 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 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 5.
4	INSPECT IG1 CIRCUIT (BETWEEN REAR CLIMATE CONTROL UNIT AND C/U IG1 15 A FUSE) FOR OPEN CIRCUIT • Rear climate control unit connector is disconnected. • Switch the ignition ON (engine off or on). • Measure the voltage at the following terminal (wiring harness-side): ? Rear climate control unit terminal X • Is the voltage B+?	Yes	Go to the next step.
4		No	Refer to the wiring diagram and verify whether or not there is a common connector between battery positive terminal and rear 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 the next step.
5	VERIFY THAT SAME DTC IS NOT OUTPUT AGAIN • Reconnect the disconnected connectors. • Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Clear the DTC from the climate control unit memory using the M-MDS. (See CLEARING DTC [CLIMATE CONTROL UNIT (FULL-AUTO AIR CONDITIONER)].) • Perform the DTC inspection for the climate control unit using the M-MDS. (See DTC DISPLAY [CLIMATE CONTROL UNIT (FULL-AUTO AIR CONDITIONER)].) • Is the same DTC displayed?	Yes	Repeat the inspection from Step 1. • If the malfunction recurs, replace the rear climate control unit. (See REAR CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.) Go to the next step.
5		No	Go to the next step.
6	VERIFY THAT NO OTHER DTCs ARE PRESENT • Verify other DTCs displayed. • Are any other DTCs displayed?	Yes	Repair or replace the malfunctioning part according to the applicable DTC troubleshooting. (See DTC TABLE [CLIMATE CONTROL UNIT (FULL-AUTO AIR CONDITIONER)].)
6		No	DTC troubleshooting completed.