DTC B108E-1C; Low Power Supply Voltage Input To Center Display

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.

DETECTION CONDITION & POSSIBLE CAUSE

Description	Low power supply voltage input to center display
Detection condition	The connectivity master unit detected any of the following conditions for 5 s or more with the ignition switched ON (engine off or on). TFT LCD driver voltage 3.8 V or less LED drive voltage 14.0 V or less Touch panel IC voltage 3.9 V or less
Fail-safe function	Stops operation of the center display.
Possible cause	DTCs are stored in the PCM. Battery malfunction Generator malfunction Center display connector or terminal malfunction Center display B+ power supply circuit malfunction Short to ground in wiring harness between MAIN 200 A fuse and center display terminal 1H ROOM 15 A fuse malfunction MAIN 200 A fuse malfunction Open circuit in wiring harness between battery and center display terminal 1H Center display ACC power supply circuit malfunction Short to ground in wiring harness between MIRROR 7.5 A fuse and center display terminal 1G MIRROR 7.5 A fuse malfunction Open circuit in wiring harness between ACC relay and center display terminal 1G Center display malfunction Connectivity master unit malfunction

DIAGNOSTIC PROCEDURE

Step	Inspection		Action
1	VERIFY PCM DTCs Perform the DTC inspection for the PCM using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-G 2.0, SKYACTIV-G 2.5)] .) Is a DTC displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting. (See DTC TABLE [PCM (SKYACTIV-G 2.0, SKYACTIV-G 2.5)] .)
1		No	Go to the next step.
2	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.
2		No	Recharge or replace the battery, then go to Step 8. (See BATTERY RECHARGING [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) (See BATTERY REMOVAL/INSTALLATION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .)
3	INSPECT GENERATOR Inspect the generator. (See GENERATOR INSPECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5 (WITHOUT i-ELOOP)] .) (See GENERATOR INSPECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5 (WITH i-ELOOP)] .) Is the generator normal?	Yes	Go to the next step.
3		No	Replace the generator, then go to Step 8. (See GENERATOR REMOVAL/INSTALLATION [SKYACTIV-G 2.0, SKYACTIV-G 2.5 (WITHOUT i-ELOOP)] .) (See GENERATOR REMOVAL/INSTALLATION [SKYACTIV-G 2.0, SKYACTIV-G 2.5 (WITH i-ELOOP)] .)
4	INSPECT CENTER DISPLAY CONNECTOR CONDITION Switch the ignition off. Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Disconnect the center display connector. Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection. Is the connector normal?	Yes	Go to the next step.
4		No	Repair or replace the connector, then go to Step 8.
5	VERIFY CENTER DISPLAY B+ POWER SUPPLY VOLTAGE Reconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Measure the voltage at center display terminal 1H (wiring harness-side). Is the voltage B+?	Yes	Go to the next step.
5		No	Install the ROOM 15 A fuse and MAIN 200 A fuse. If any fuse is blown: Refer to the wiring diagram and verify if there is a common connector between MAIN 200 A fuse and center display terminal 1H. If there is a common connector: Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for short to ground to determine the malfunctioning location. Repair or replace the malfunctioning location. If there is no common connector: Repair or replace the wiring harness which is shorted to ground. Replace the fuse. If any fuse is damaged: Replace the fuse. If the fuses are normal: Refer to the wiring diagram and verify if there is a common connector between positive battery terminal and center display terminal 1H. If there is a common connector: Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for an open circuit to determine the malfunctioning location. Repair or replace the malfunctioning location. If there is no common connector: Repair or replace the wiring harness which has an open circuit. Go to Step 8.
6	VERIFY CENTER DISPLAY ACC POWER SUPPLY VOLTAGE Measure the voltage at center display terminal 1G (wiring harness-side). Is the voltage B+?	Yes	Go to the next step.
6		No	Inspect the MIRROR 7.5 A fuse. If the fuse is blown: Refer to the wiring diagram and verify if there is a common connector between MIRROR 7.5 A fuse and center display terminal 1G. If there is a common connector: Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for short to ground to determine the malfunctioning location. Repair or replace the malfunctioning location. If there is no common connector: Repair or replace the wiring harness which is shorted to ground. Replace the fuse. If the fuse is damaged: Replace the fuse. If the fuse is normal: Refer to the wiring diagram and verify if there is a common connector between ACC relay and center display terminal 1G. If there is a common connector: Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for an open circuit to determine the malfunctioning location. Repair or replace the malfunctioning location. If there is no common connector: Repair or replace the wiring harness which has an open circuit. Go to Step 8.
7	PERFORM DTC INSPECTION AND VERIFY IF MALFUNCTIONING LOCATION IS CENTER DISPLAY Clear the DTC for the connectivity master unit using the M-MDS. (See CLEARING DTC [CONNECTIVITY MASTER UNIT] .) Switch the ignition ON (engine off or on) and wait for 12 s or more. Perform the DTC inspection for the connectivity master unit using the M-MDS. (See DTC INSPECTION [CONNECTIVITY MASTER UNIT] .) Is the same DTC displayed?	Yes	Replace the center display, then go to the next step. (See CENTER DISPLAY REMOVAL/INSTALLATION .)
7		No	Go to Step 9.
8	VERIFY THAT REPAIRS HAVE BEEN COMPLETED Always reconnect all disconnected connectors. Reconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Clear the DTC for the connectivity master unit using the M-MDS. (See CLEARING DTC [CONNECTIVITY MASTER UNIT] .) Switch the ignition ON (engine off or on) and wait for 12 s or more. Perform the DTC inspection for the connectivity master unit using the M-MDS. (See DTC INSPECTION [CONNECTIVITY MASTER UNIT] .) Is the same DTC displayed?	Yes	Repeat the inspection from Step 1. If the malfunction recurs, replace the connectivity master unit. (See CONNECTIVITY MASTER UNIT (CMU) REMOVAL/INSTALLATION .) Go to the next step.
8		No	Go to the next step.
9	VERIFY IF OTHER DTCs DISPLAYED Are any other DTCs displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting. (See DTC TABLE [CONNECTIVITY MASTER UNIT] .)
9		No	DTC troubleshooting completed.