DTC P1550 P1551 P1552 2AD-FHV

DTC P1550 Battery Current Sensor Circuit

DTC P1551 Battery Current Sensor Circuit Low

DTC P1552 Battery Current Sensor Circuit High

 

Description

The battery current sensor installed on the positive battery terminal detects the amount of current supplied from the alternator.
Description DTC P1550 DTC P1551 DTC P1552
The battery current sensor changes current to voltage and outputs that voltage. The battery current sensor changes current at the positive battery terminal to voltage and sends it to the ECM. The ECM controls the voltage of the alternator based on the signals from the battery current sensor.
Toyota fault code list DTC P1550 DTC P1551 DTC P1552

DTC No. DTC Detection Condition Trouble Area
P1550 The following condition continues for 10 seconds or more with the ignition 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. Battery current sensor
  2. Wire harness or connector
  3. ECM
P1551 Battery current sensor output value is 0.2 V or less for 0.55 seconds or more with the ignition switch on (IG)
(1 trip detection logic)
  1. Battery current sensor
  2. Wire harness or connector
  3. ECM
P1552 Battery current sensor output value is 4.8 V or more for 0.55 seconds or more with the ignition switch on (IG)
(1 trip detection logic)
  1. Battery current sensor
  2. Wire harness or connector
  3. ECM

Wiring diagram

Refer to DTC P0516.

Inspection procedure

 

NOTICE:

After replacing the ECM, the new ECM needs registration and initialization.

HINT:

If DTCs relating to different systems are output, and they share terminal E2 as their ground, check this ground circuit first.

 

1.INSPECT BATTERY CURRENT SENSOR ASSEMBLY

Inspect battery current sensor assembly

  1. Disconnect the B31 battery current sensor connector.

  2. Measure the resistance of the battery current sensor.

     

    Standard resistance:

    Tester Connection Specified Condition
    B31-2 (VC5) - B31-4 (E2) 3 to 10 k?
    B31-3 (IB)- B31-4 (E2) 3 to 10 k?
    B31-2 (VC5) - B31-3 (IB) Below 0.5 k?

    HINT:

    The resistance differs according to the tester type.

  3. Reconnect the battery current sensor connector.

 

  NG  
REPLACE BATTERY CURRENT SENSOR ASSEMBLY
 
OK  
   
2.CHECK WIRE HARNESS (BATTERY CURRENT SENSOR - ECM)

Check wire harness (battery current sensor - ecm)

  1. Disconnect the B31 battery current sensor connector.

  2. Disconnect the B32 ECM connector.

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

     

    Standard resistance:

    Tester Connection Specified Condition
    B31-2 (VC5) - B32-70 (VCIB) Below 1 ?
    B31-3 (IB)- B32-116 (IB) Below 1 ?
    B31-4 (E2) - E1 (B32-109) Below 1 ?
    B31-2 (VC5) or B32-70 (VCIB) - Body ground 10 k? or higher
    B31-3 (IB)or B32-116 (IB) - Body ground 10 k? or higher

  4. Reconnect the battery current sensor connector.

  5. Reconnect the ECM connector.

 

  NG  
REPAIR OR REPLACE HARNESS AND CONNECTOR
 
OK  
   
REPLACE ECM 
2AD-FHV