DTC P0B3C:00 OR P0B3E:00 [Mazda M Hybrid BATTERY]

Description	P0B3C:00: Mazda M Hybrid battery (cell voltage sensor): Sensor characteristic malfunction P0B3E:00: Mazda M Hybrid battery (cell voltage sensor): High input
Detection condition	Determination conditions	P0B3C:00 • The difference between the measured value of the voltage sensor measuring the voltage at each cell (No.1—No.9) in the Mazda M Hybrid battery and the measured value of the voltage sensor which constantly monitors the voltage at each cell is more than 0.3 V.
	Determination conditions	P0B3E:00 • The following conditions are met: ― Voltage at each cell (No.1—No.9) in Mazda M Hybrid battery is more than 4.5 V ― Difference between sum of voltage at each cell (No.1—No.9) in Mazda M Hybrid battery and total voltage monitor is more than 0.6 V
	Preconditions	• Mazda M Hybrid battery is any of the following conditions (PID: BECM_STAT) ― INITIAL ― STANDBY ― PRECHARGE ― READY • The following DTCs are not detected: P0B3C:00 ― P1B04:33 and P1B04:81 P0B3E:00 ― P1B04:33, P1B04:81, P0ABC:00 and P0ABD:00
	Malfunction determination period	• 3 s period
	Drive cycle	• 1
	Self test type	• CMDTC self test, ODDTC self test
	Sensor used	• Mazda M Hybrid battery
Fail-safe function	• The integrated starter generator (ISG) only generates power required for power supply to the 12 V system. • Inhibits the i-stop control. • Inhibits the non-power generation control. • Inhibits regenerative braking by the integrated starter generator (ISG). • Inhibits motor assist control by the integrated starter generator (ISG).
Vehicle status when DTCs are output	• Inhibits the i-stop control.
Possible cause	• Mazda M Hybrid battery malfunction

• There are two types of cell voltage sensors in the Mazda M Hybrid battery, measurement system and the constant monitor system, the output value of each sensor is compared and if the difference between the voltages is more than 0.3 V for a continuous 3 s, the Mazda M Hybrid battery determines a malfunction and stores a DTC.

• When the sum of the cell voltage in the Mazda M Hybrid battery is compared with the measured voltage of the overall Mazda M Hybrid battery and the difference between the voltages is more than 0.6 V for a continuous 3 s, the Mazda M Hybrid battery determines a malfunction and stores a DTC.

1. Start the engine.

2. Perform the road test.

Note

• When an upward motion vibration is applied such as when driving over an uneven road, the Mazda M Hybrid battery could display a DTC.

• Perform the road test on an uneven road.

Step	Inspection	Results	Action
1	RECORD VEHICLE STATUS WHEN DTC WAS DETECTED TO UTILIZE WITH REPEATABILITY VERIFICATION • Record the snapshot data. Note • Recording can be facilitated using the screen capture function of the PC.	—	Go to the next step.
2	VERIFY WHETHER MALFUNCTION IS PRESENT OR PAST • Perform the DTC inspection for the Mazda M Hybrid battery. (See DTC INSPECTION.) • Is DTC P0B3C:00 or P0B3E:00 a present malfunction?	Yes	Go to the next step.
2		No	Go to Step 4.
3	VERIFY WHETHER MALFUNCTION IS PRESENT OR PAST AGAIN • Switch the ignition off. • Switch the ignition ON (engine off or on) and wait for 10 s or more. • Perform the DTC inspection for the Mazda M Hybrid battery. (See DTC INSPECTION.) • Is DTC P0B3C:00 or P0B3E:00 a present malfunction?	Yes	Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].) If the CAN communication is normal, perform the diagnosis from Step 1. • If the malfunction recurs, replace the Mazda M Hybrid battery and perform the repair completion verification. (See Mazda M Hybrid BATTERY REMOVAL/INSTALLATION.)
3		No	Go to the next step.
4	INSPECT Mazda M Hybrid BATTERY FOR MALFUNCTION DEPENDING ON REPEATABILITY • Implement the repeatability verification procedure. (See Repeatability Verification Procedure.) • Perform the DTC inspection for the Mazda M Hybrid battery. (See DTC INSPECTION.) • Is DTC P0B3C:00 or P0B3E:00 a present malfunction?	Yes	Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].) If the CAN communication is normal, perform the diagnosis from Step 1. • If the malfunction recurs, replace the Mazda M Hybrid battery and perform the repair completion verification. (See Mazda M Hybrid BATTERY REMOVAL/INSTALLATION.)
4		No	The system is normal. (Explain to the customer that a DTC may be displayed when large vibration is applied in the upward/downward direction such as when driving over an uneven road.) Go to the next step.
Repair completion verification	VERIFY IF OTHER DTCs DISPLAYED • Perform the DTC inspection. (See DTC INSPECTION.) • Are any other DTCs displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting.
Repair completion verification		No	DTC troubleshooting completed.

Mazdamanuals.com