Dtc P1550 Battery Current Sensor Circuit

Engine. Lexus Gs430, Gs300. Uzs190 Grs190
3Gr-Fse Engine Control System. Lexus Gs430, Gs300. Uzs190 Grs190

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

INSPECT BATTERY CURRENT SENSOR ASSEMBLY

CHECK HARNESS AND CONNECTOR (BATTERY CURRENT SENSOR - ECM)

DTC P1550 Battery Current Sensor Circuit

DTC P1551 Battery Current Sensor Circuit Low

DTC P1552 Battery Current Sensor Circuit High


DESCRIPTION

Lexus Gs430, Gs300. Uzs190 Grs190.3Gr-Fse Engine Control System.Sfi System. Dtc P1550 Battery Current Sensor Circuit
The battery current sensor installed on the positive (+) battery terminal detects the amount of current supplied from the generator.
The battery current sensor changes current to voltage (at the positive (+) battery terminal) and sends it to the ECM. The ECM controls the voltage of the generator based on the signals from the battery current sensor.

DTC No.
DTC Detection Condition
Trouble Area
P1550
The following condition continues for 10 seconds or more with the engine switch on (IG)
(1 trip detection logic):
  1. Difference between the maximum and minimum current values of the battery current sensor is 1 A or less
  1. Open or short in battery current sensor circuit
  2. Battery current sensor assembly
  3. ECM
P1551
Battery current sensor output value is 0.2 V or less for 0.5 seconds or more with the engine switch on (IG)
(1 trip detection logic):
  1. Short in battery current sensor circuit
  2. Battery current sensor assembly
  3. ECM
P1552
Battery current sensor output value is 4.8 V or more for 0.5 seconds or more with the engine switch on (IG)
(1 trip detection logic):
  1. Open in battery current sensor circuit
  2. Battery current sensor assembly
  3. ECM

WIRING DIAGRAM


Lexus Gs430, Gs300. Uzs190 Grs190.3Gr-Fse Engine Control System.Sfi System. Dtc P1550 Battery Current Sensor Circuit


INSPECTION PROCEDURE

HINT:
  1. If different DTCs that are related to a different system are output simultaneously while terminal E3 is used as a ground terminal, terminal E3 may be open.
  2. Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
1.INSPECT BATTERY CURRENT SENSOR ASSEMBLY
Lexus Gs430, Gs300. Uzs190 Grs190.3Gr-Fse Engine Control System.Sfi System. Dtc P1550 Battery Current Sensor Circuit

  1. Disconnect the A46 battery thermometer sensor connector.

  1. Measere the resistance of the battery current sensor.

    Standard resistance:
    Tester Connection
    		Specified Condition
    VC5 (3) - E2 (2)
    		3 to 6 or 0.7 to 8 kΩ
    VC5 (3) - IB (1)
    		0.2 to 0.3 or 0.2 to 3 kΩ
    IB (1) - E2 (2)
    		1.5 to 8 or 3 to 6 kΩ
    HINT:
    The resistance differs according to the tester type.


NG
REPLACE BATTERY CURRENT SENSOR ASSEMBLY
OK


2.CHECK HARNESS AND CONNECTOR (BATTERY CURRENT SENSOR - ECM)
Lexus Gs430, Gs300. Uzs190 Grs190.3Gr-Fse Engine Control System.Sfi System. Dtc P1550 Battery Current Sensor Circuit

  1. Check the harness and the connectors between the ECM and the battery current sensor.

    1. Disconnect the battery current sensor connector.

    2. Disconnect the A7and E6 ECM connectors.

    3. Measure the resistance of the wire harness side connectors.

      Standard resistance (Check for open):
      Tester Connection
      		Specified Condition
      IB (A46-1) - IB (A7-24)
      		Below 1 Ω
      VC5 (A46-3) - VCP2 (A7-27)
      		Below 1 Ω
      E2 (A46-2) - E3 (E6-30)
      		Below 1 Ω
      Standard resistance (Check for short):
      Tester Connection
      		Specified Condition
      IB (A46-1) or IB (A7-24) - Body ground
      		10 kΩ or higher
      VC5 (A46-3) or VCP2 (A7-27) - Body ground
      		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK

REPLACE ECM