Subaru BRZ 2013 · Service Manual Power supply/communication system

Charging system (FA20)

Precautions Parts location System information Troubleshooting Diagnostic trouble codes Inspection

BATTERY / CHARGING
CHARGING SYSTEM (FA20)
PRECAUTIONS
1. Never disconnect the battery while the engine is running.
2. Check that the battery cables are correctly connected to the terminals.
3. Do not connect the battery cables during quick charging.
PARTS LOCATION
ON-VEHICLE INSPECTION
CAUTION:
·Never disconnect the battery while the engine is running.
·Check that the battery cables are correctly connected to the terminals.
·Do not connect the battery cables during quick charging.
1. Inspection of the battery fluid level
(1) Fluid level inspection
(a) If the level is below LOW, either replace the battery or replenish the level by pouring in distilled water.
2. Checking of the battery specific gravity
(1) Check the specific gravity of the fluid in each battery cell.
Standard value :  1.25 - 1.29 (At fluid temperature of 20°C {68°F})
NOTE:
If this is less than the standard value, recharge the battery.
3. Battery voltage check
(1) In order to remove the surface charge, with the ignition turned to IG OFF, turn the headlight switch to ON for approximately 20 to 30 seconds.
(2) Turn the headlight switch to OFF.
(3) Measure the battery voltage between terminals.
Voltage
Inspection terminals
 Inspection conditions
 Standard value
Positive battery terminal - Negative battery terminal
 Fluid temperature 20°C {68°F}
12.5 - 12.9 V
NOTE:
If this is less than the standard value, recharge the battery.
4. Inspection of the battery terminals, fusible links, and fuses
(1) Check that the battery terminals are not loose or corroded.
(2) Check that there is continuity through the fusible links and fuses.
6. Inspection of the alternator wiring harness
(1) Check that there are no cracks or deterioration in the wiring harness.
7. Checking for strange noises originating from the alternator
(1) Check that no strange noises come from the alternator during engine starting.
8. Inspection of the charge warning light
(1) Warm up the engine and turn the ignition to IG OFF.
(2) Turn all of the electrical device switches to OFF.
(3) Turn the ignition to IG ON and confirm that the charge warning light illuminates.
(4) Confirm that this light turns off after starting the engine.
NOTE:
If the light does not behave as specified above, perform troubleshooting for the charge warning light circuit.
9. No load test
(1) Inspection of the charging circuit
(a) When under no load, measure the battery voltage when the engine speed is increased up to 2000 r/min.
Voltage
Inspection terminals
 Inspection conditions
 Standard value
B terminal - Chassis ground
 20 A or less
 11.3 - 15.6 V
Captions in illustration
*1
 B Terminal
*2
 Battery
*3
 Alternator
*4
 AC/DC 400 A probe
*a
 Current
CHECKING / CLEARING DIAGNOSTIC CODES
1. Checking diagnostic codes (with the SSM3)
(1) With the ignition turned to IG OFF, connect the SSM3 to the DLC3.
(2) Turn IG to ON, and turn on the SSM3.
(3) Follow the SSM3 display and select [ BRZ Check]→[Each System Check]→[Engine Control System]→[Diagnostic Code(s) Display] to check the diagnostic codes.
2. Clearing of recorded diagnostic codes (with the SSM3)
(1) With the ignition turned to IG OFF, connect the SSM3 to the DLC3.
(2) Turn IG to ON, and turn on the SSM3.
(3) Follow the SSM3 display and select [ BRZ Check]→[Each System Check]→[Engine Control System]→[Clear Memory] to delete the diagnostic codes.
CAUTION:
·If deletion is not possible, retry it after turning the ignition to IG OFF and then on again.
·Do not use the SSM3 to delete diagnostic codes until the cause of the trouble has been identified.
CIRCUIT FIGURE
CURRENT DATA DISPLAY & SAVE / SYSTEM OPERATION CHECK MODE
1. Current Data Display & Save
(1) Use the SSM3 and follow the display to bring up the [Normal sampling] screen in order to inspect the computer data.
CAUTION:
Due to slight measurement differences and factors such as differences in the measurement environment or vehicle aged-related variation, the current data display & save / system operation check mode value can be widely varied. It is difficult to obtain a precise standard value (determined value) for this. Therefore, there may be cases where a fault is present, even if it is within the reference value.
SSM3 screen: [BRZ Check] → [Each System Check] → [Engine Control System]→[Current Data Display & Save] → [Normal sampling]
Item name
 Description/display range
 Normal value
 Remarks
(Main inspection items during a malfunction)
[Control module voltage]
·Indicates the battery voltage.
·Display range: 0 - 65.535 V
 11 to 14 V: At idling speed
Reference value:
·IG ON: 12.5 V
·While cranking: 9.834 V
·At idling speed (after being warmed up): 13.359 V
If the battery voltage 11 V or less, other systems may be affected.
[Battery Current]
·Indicates the battery current.
·Display range: -125 - 125 A
 Changes depending on the alternator generation amount: After warming up, when driving
 When a malfunction occurs, it may be due to a problem with the IB voltage system or sensor power supply.
[Battery Temperature]
·Indicates the battery ambient temperature which is calculated from the output from the battery temperature sensor (battery current sensor ASSY).
·Display range: -40 to 6513.5°C {-40 to 11756.3°F}
Changes depending on the actual temperature: After warming up, when driving
 When a malfunction occurs, it may be due to a problem with the THB voltage system or sensor power supply.
[Alt Vol - Non Active Test]
·Indicates the requested voltage when forced driving of the regulator is not being carried out.
·Display range: 0 - 80 V
 Changes depending on the battery fluid temperature, driving conditions (12.4 - 14.8 V): After engine is started
 When a malfunction occurs, it may be due to a problem with the charging control system.
[Alt Vol - Active Test]
·Indicates the requested voltage when forced driving of the regulator is being carried out.
·Display range: 0 - 80 V
 Value of the request instruction voltage when system operation check mode [Alternator control] is carried out: After engine is started
·Indicates the generation voltage during [System Operation Check Mode].
·When a malfunction occurs, it may be due to a problem with the charging control system.
[ALT Duty]
·Indicates the charging control signal.
·Display range: 0 - 255 %
 Changes depending on the alternator generation amount: During charging control
 When a malfunction occurs, it may be due to a problem with the charging control system.
[Alternator control mode]
·Indicates the alternator generation control mode.
·Display range: 0 - 255 %
 Changes depending on the alternator generation amount: During charging control
 When a malfunction occurs, it may be due to a problem with the charging control system.
2. System operation check mode.
(1) Use the SSM3 and follow the display to bring up the [System Operation Check Mode] screen in order to perform a system operation check.
SSM3 screen: [Engine Control System] → [Work Support] → [System Operation Check Mode]
Item
 Contents
 Restrictions
[Alternator control]
 Increases or decreases the alternator generation request voltage.
Able to request within the range of 12.8 - 14.1 V.
 While engine running
DTCP0516 Battery temperature sensor circuit (LOW)
DTCP0517 Battery temperature sensor circuit (HIGH)
Circuit description
The battery temperature sensor detects the battery temperature. The thermistor that is built into the battery current sensor changes its resistance according to fluctuations in the battery temperature. As the battery temperature decreases, the thermistor resistance becomes higher. As it increases, this value becomes lower. The battery temperature sensor is connected to the engine control computer. The 5 V power supply voltage inside the engine control computer passes through the resistance and the THB terminal supplies the battery temperature sensor. In other words, because the resistance and the battery temperature sensor are connected in series, the resistance changes according to fluctuations in the battery temperature which means the THB terminal potential also changes. According to this signal, the engine control computer lowers the alternator adjustment current and reduces the recharge current when the battery temperature is high in order to protect the battery. [Current Data Display & Save]
DTC NO.
 Detecting conditions
1. Diagnosis condition
2. Abnormal condition
3. Abnormal period
4. Other
 Inspection parts
P0516
1. The engine speed is 500 r/min or more, the battery voltage is 10.9 V or more, one second or more has passed since the engine started.
2. The battery temperature sensor output value is less than 0.104 V.
3. 0.5 seconds or more
4. 1 trip
·Battery current sensor ASSY
·Wiring harness or connector
·Engine control computer
P0517
1. The engine speed is 500 r/min or more, the battery voltage is 10.9 V or more, one second or more has passed since the engine started.
2. The battery temperature sensor output value is 4.867 V or more.
3. 0.5 seconds or more
4. 1 trip
·Battery current sensor ASSY
·Wiring harness or connector
·Engine control computer
DTCP1530 Battery current sensor circuit (LOW)
DTCP1531 Battery current sensor circuit (HIGH)
DTCP1532 Charging control system
Circuit description
The battery current sensor ASSY detects the amount of battery charging and discharging current. It converts the signal into a voltage and outputs it to the engine control computer. The engine control computer uses this signal to send generation voltage instructions to the alternator.
DTC NO.
 Detecting conditions
1. Diagnosis condition
2. Abnormal condition
3. Abnormal period
4. Other
 Inspection parts
P1530
1. The engine speed is 500 r/min or more, the battery voltage is 10.9 V or more, one second or more has passed since the engine started.
2. The current sensor ASSY output value is less than 0.347 V.
3. 0.5 seconds or more
4. 1 trip
·Battery current sensor ASSY
·Wiring harness or connector
·Engine control computer
P1531
1. The engine speed is 500 r/min or more, the battery voltage is 10.9 V or more, one second or more has passed since the engine started.
2. The current sensor ASSY output value is 4.653 V or more.
3. 0.5 seconds or more
4. 1 trip
·Battery current sensor ASSY
·Wiring harness or connector
·Engine control computer
P1532
1. IG ON
2. [Current sensor sticking diagnosis] The difference between the maximum and minimum voltages when switching between charging states is less than 0.07 V; [Charging side characteristics diagnosis] After the alternator target duty drops from 60% or more to less than 40%, while it remains less than 40%, the battery voltage is less than 13.2 V and the battery current sensor voltage is 2.6 V or more and less than 5 V; [Discharging side characteristics diagnosis] After the alternator target duty rises from less than 40% to 60% or more, while it remains 60% or more, the battery voltage is 13.7 V or more, and the battery current sensor voltage is 0 V or more and less than 2.4 V.
3. [Current sensor sticking diagnosis] The charging state is switched over ten times or more in succession when it is in an abnormal state; [Charging side characteristics diagnosis] 30 seconds or more; [Discharging side characteristics diagnosis] 30 seconds or more.
4. 1 trip
·Battery current sensor ASSY
·Wiring harness or connector
·Engine control computer
Circuit figure
Inspection steps
2. Read of the SSM3 data (Battery current)

(1) Connect the SSM3 to the DLC3.
(2) Turn the ignition to IG ON, and turn all the electrical device (headlights, blower motor, wiper, rear defogger, etc) switches to OFF.
(3) Use the SSM3 and follow the display to read the [Normal sampling] - [Battery Current] information. (Refer to )
Result
Result
 Go to
Fixed at 0 A with no observable variation, or there is only variation of less than 1 A between -100 - 100 A.
 A
Varies between -20 - 0 A.
 B
B
>Inspection for problems that do not normally occur (Refer to )

A▼