DTC P1530 Battery Current Sensor Circuit Low: Notes

DTC detecting condition:

Immediately at fault recognition

CAUTION:

After servicing or replacing faulty parts, perform Clear Memory Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Clear Memory Mode . and Inspection Mode Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Inspection Mode .
Use the check board when measuring the ECM terminal voltage and resistance.

Wiring diagram:

Engine Electrical System Ref. to WIRING SYSTEM>Engine Electrical System>WIRING DIAGRAM .

Fig 1: Battery Current Sensor Circuit Low - Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

CHECK CURRENT DATA.
1. Start the engine.
2. Read the value of Battery current value using the Subaru Select Monitor.
NOTE: For detailed procedures, refer to "Data Monitor". Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Subaru Select Monitor .

Is the value of Battery current value 100 A or more?
- Yes : Go to 2.
- No : Even if DTC is detected, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis.
NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.
CHECK HARNESS BETWEEN ECM AND BATTERY CURRENT & TEMPERATURE SENSOR CONNECTOR.
1. Turn the ignition switch to OFF.
2. Disconnect the connectors from the battery current & temperature sensor.
3. Disconnect the connector from ECM.
4. Measure the resistance of harness between ECM and battery current & temperature sensor connector.
  Connector & terminal
  
  (B134) No. 18 - (B472) No. 2:
  
  (B134) No. 42 - (B472) No. 3:
  
  Is the resistance less than 1 Ω?
  - Yes : Go to 3.
  - No : Repair the open circuit of harness between ECM and battery current & temperature sensor connector.
CHECK HARNESS BETWEEN ECM AND BATTERY CURRENT & TEMPERATURE SENSOR CONNECTOR.
Measure the resistance between ECM and engine ground.

Connector & terminal

(B134) No. 18 - Engine ground:

(B134) No. 42 - Engine ground:

Is the resistance 1 MΩ or more?
- Yes : Go to 4.
- No : Repair the ground short circuit of harness between ECM and battery current & temperature sensor connector.
CHECK FOR POOR CONTACT.
Check for poor contact between the ECM and battery current & temperature sensor connectors.

Is there poor contact of the ECM or battery current & temperature sensor connectors?
- Yes : Repair any poor contact between the ECM or battery current & temperature sensor connectors.
- No : Replace the battery current & temperature sensor. Ref. to STARTING/CHARGING SYSTEMS(H4DO)>Battery Current & Temperature Sensor .