EC-390
< COMPONENT DIAGNOSIS >
[VQ35HR]
P1554 BATTERY CURRENT SENSOR
P1554 BATTERY CURRENT SENSOR
Description
INFOID:0000000000956789
The power generation voltage variable control enables fuel consumption to be decreased by reducing the
engine load which is caused by the power generation of the generator. The battery current sensor is installed
to the battery cable at the negative terminal. The sensor measures the charging/discharging current of the bat-
tery. Based on the sensor signal, ECM judges whether or not the power generation voltage variable control is
performed. When performing the power generation voltage variable control, ECM calculates the target power
generation voltage based on the sensor signal. And ECM sends the calculated value as the power generation
command value to IPDM E/R. For the details of the power generation voltage variable control, refer to
CHG-8,
"System Description"
.
CAUTION:
Do not connect the electrical component or the ground wire directly to the battery terminal. The con-
nection causes the malfunction of the power generation voltage variable control, and then the battery
discharge may occur.
DTC Logic
INFOID:0000000000956790
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.
PERFORM COMPONENT FUNCTION CHECK
Perform component function check. Refer to
EC-390, "Component Function Check"
.
NOTE:
Use component function check to check the overall function of the battery current sensor circuit. During this
check, a 1st trip DTC might not be confirmed.
Is the inspection result normal?
YES
>> INSPECTION END
NO
>> Go to
EC-391, "Diagnosis Procedure"
.
Component Function Check
INFOID:0000000000956791
1.
PRECONDITIONING
TESTING CONDITION:
• Before performing the following procedure, confirm that battery voltage is more than 12.8V at idle.
DTC No.
Trouble diagnosis name
DTC detecting condition
Possible cause
P1554
Battery current sensor perfor-
mance
The output voltage of the battery current
sensor is lower than the specified value
while the battery voltage is high enough.
• Harness or connectors
(Battery current sensor circuit is open
or shorted.)
[CKP sensor (POS) circuit is shorted.]
[CMP sensor (PHASE) (bank 2) circuit
is shorted.]
[EVT control position sensor (bank 2)
circuit is shorted.]
(APP sensor 2 circuit is shorted.)
(EVAP control system pressure sensor
circuit is shorted.)
(Refrigerant pressure sensor circuit is
shorted.)
• Battery current sensor
• Crankshaft position sensor (POS)
• Camshaft position sensor (PHASE)
(bank 2)
• Exhaust valve timing control position
sensor (bank 2)
• Accelerator pedal position sensor
• EVAP control system pressure sensor
• Refrigerant pressure sensor