Discharged 12V Battery

DISCHARGED 12V BATTERY

Description


DESCRIPTION

12V batteries go dead due to diverse factors, such as 12V battery deterioration, poor power generation in DC/
DC junction box, driving condition, malfunctioning wiring or control unit. In this case, it is important for the correct diagnosis to check vehicle condition, battery saver function condition, and operating state of the power consumption control system (sleep function), in addition to an interview to the customer.
NOTE:
For battery saver function and the power consumption control system (sleep function), refer to the following items:
- Exterior lamp battery saver system: {LINK_TO:0000000007635294}, "EXTERIOR LAMP BATTERY SAVER SYSTEM : System
Description"
- Interior room lamp battery saver system: {LINK_TO:0000000007632650}, "INTERIOR ROOM LAMP BATTERY SAVER SYSTEM :
System Description"
- Power consumption control system (sleep function): "POWER CONSUMPTION CONTROL SYSTEM : System Description" Power Consumption Control System
For an interview, obtain detailed information about the following items as much as possible:
- History of 12V battery replacement by the customer
- Usual usage pattern
- Usage pattern immediately before the 12V battery goes dead or the situation at parking.

INTERVIEW

Work history





Usual usage pattern





Usage pattern immediately before the occurrence of malfunction





Situation at parking immediately before the occurrence of the malfunction





Vehicle condition at the occurrence of malfunction







Diagnosis Procedure


1. CHECK INTERVIEW RESULT AND VEHICLE CONDITION

Check the use pattern of before and after the occurrence of malfunction and the vehicle condition of after the occurrence of the malfunction. Refer to "Description" .

CAUTION:
To perform a field repair for a dead 12V battery, check the vehicle condition before restarting with a booster cable and measure battery voltage, specific gravity of battery fluid, and dark current (with/
without the jumping battery connection) to perform a correct diagnosis.
- GO TO 2.

2. CHECK 12V BATTERY

Check 12V battery. Refer to "Work Flow" Testing and Inspection.
- GO TO 3.

3. CHECK 12V BATTERY CHARGE WARNING LAMP

1.Set the vehicle to READY.
2.Be sure that 12V battery charge warning lamp is turned off.
Inspection result
Turned off-GO TO 4.
Not turned off-Perform VCM self-diagnosis. Refer to "CONSULT Function" VCM.

4. CHECK DARK CURRENT

Check dark current. Refer to "Work Procedure" Initial Inspection and Diagnostic Overview.
Is the inspection result normal?
YES- It can be considered that the current consumer is more than the power generation capacity of the
DC/DC junction box. Recheck the installation condition of commercial after parts and the customer's use pattern.
NO- Check and repair applicable part, according to the inspection result.