Diagnostic Procedure

WARNING: This page is about a different car, the 2017 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.

DTC U3003:16, U3003:17 (CLIMATE CONTROL UNIT - FULL-AUTO AIR CONDITIONER) DIAGNOSTIC PROCEDURE - WITH DUAL TYPE CLIMATE CONTROL UNIT

STEP	INSPECTION		ACTION
1	INSPECT PCM DTC (INSPECT GENERATOR CIRCUIT) Switch the ignition off. Connect the M-MDS to the DLC-2. Perform the PCM DTC inspection using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-G 2.0, SKYACTIV-G 2.5)] .) Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [PCM (SKYACTIV-G 2.0, SKYACTIV-G 2.5)] .)
1		No	Go to the next step.
2	INSPECT FUSE Switch the ignition off. Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Remove the ROOM 15 A fuse. Is the fuse normal?	Yes	Install the ROOM 15 A fuse, then go to the next step.
2		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 6.
3	INSPECT BATTERY Inspect the battery. (See BATTERY INSPECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Is the battery normal?	Yes	Go to the next step.
3		No	Replace or charge the battery. (See BATTERY REMOVAL/INSTALLATION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) (See BATTERY RECHARGING [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Then go to Step 6.
4	VERIFY CLIMATE CONTROL UNIT CONNECTOR CONDITION Disconnect the climate control unit connector. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER] .) Inspect the connector and terminals (corrosion, damage, pin disconnection). Are the connector and terminals normal?	Yes	Go to the next step.
4		No	Repair/replace the connector or terminal. After repair procedure, go to Step 6.
5	INSPECT CLIMATE CONTROL UNIT POWER SUPPLY CIRCUIT FOR OPEN CIRCUIT Inspect for continuity between the following terminals (wiring harness-side) and battery positive terminal. Climate control unit terminal 1B Is there continuity?	Yes	Go to the next step.
5		No	Refer to the wiring diagram and verify whether or not there is a common connector between climate control unit terminal and battery positive 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 cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) 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 climate control unit. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER] .) 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.

DTC U3003:16, U3003:17 (CLIMATE CONTROL UNIT - FULL-AUTO AIR CONDITIONER) DIAGNOSTIC PROCEDURE - WITH SINGLE TYPE CLIMATE CONTROL UNIT

STEP	INSPECTION		ACTION
1	INSPECT PCM DTC (INSPECT GENERATOR CIRCUIT) Switch the ignition off. Connect the M-MDS to the DLC-2. Perform the PCM DTC inspection using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-G 2.0, SKYACTIV-G 2.5)] .) Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [PCM (SKYACTIV-G 2.0, SKYACTIV-G 2.5)] .)
1		No	Go to the next step.
2	INSPECT FUSE Switch the ignition off. Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Remove the ROOM 15 A fuse. Is the fuse normal?	Yes	Install the ROOM 15 A fuse, then go to the next step.
2		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 8.
3	INSPECT BATTERY Inspect the battery. (See BATTERY INSPECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Is the battery normal?	Yes	Go to the next step.
3		No	Replace or charge the battery. (See BATTERY REMOVAL/INSTALLATION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) (See BATTERY RECHARGING [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Then go to Step 8.
4	VERIFY CLIMATE CONTROL UNIT CONNECTOR CONDITION Disconnect the climate control unit connector. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER] .) Inspect the connector and terminals (corrosion, damage, pin disconnection). Are the connector and terminals normal?	Yes	Go to the next step.
4		No	Repair/replace the connector or terminal. After repair procedure, go to the Step 8.
5	INSPECT CLIMATE CONTROL UNIT POWER SUPPLY CIRCUIT FOR OPEN CIRCUIT Inspect for continuity between the following terminals (wiring harness-side) and battery positive terminal: Climate control unit terminal L Is there continuity?	Yes	Go to the next step.
5		No	Refer to the wiring diagram and verify whether or not there is a common connector between climate control unit terminal and battery positive 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 8.
6	INSPECT CLIMATE CONTROL UNIT POWER SUPPLY CIRCUIT FOR SHORT TO GROUND Inspect for continuity between the following terminals (wiring harness-side) and body ground: Climate control unit terminal N 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 front body control module (FBCM) 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 8.
6		No	Go to the next step.
7	INSPECT CLIMATE CONTROL UNIT POWER SUPPLY CIRCUIT FOR OPEN CIRCUIT Inspect for continuity between the following terminals (wiring harness-side): Climate control unit terminal N- front body control module (FBCM) terminal 1C Is there continuity?	Yes	Go to the next step.
7		No	Refer to the wiring diagram and verify whether or not there is a common connector between climate control unit terminal and front body control module (FBCM) 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.
8	VERIFY THAT SAME DTC IS NOT OUTPUT AGAIN Reconnect the disconnected connectors. Connect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) 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 climate control unit. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER] .) Go to the next step.
8		No	Go to the next step.
9	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)] .)
9		No	DTC troubleshooting completed.