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 Mode Ref. to ENGINE (DIAGNOSTICS) (H4DO) > Clear Memory Mode > OPERATION , and Inspection Mode Ref. to ENGINE (DIAGNOSTICS) (H4DO) > Inspection Mode > PROCEDURE .

WIRING DIAGRAM:

Engine Electrical System NON-TURBO MODEL (WITHOUT PUSH BUTTON START) Ref. to WIRING SYSTEM > Engine Electrical System > NON-TURBO MODEL (WITHOUT PUSH BUTTON START) .
Engine Electrical System NON-TURBO MODEL (WITH PUSH BUTTON START) Ref. to WIRING SYSTEM > Engine Electrical System > NON-TURBO MODEL (WITH PUSH BUTTON START) .

Fig 1: Engine Electrical System Non-Turbo Model Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

CHECK CURRENT DATA .
1. Start the engine.
2. Using the Subaru Select Monitor, read the value in [Battery current value].
  NOTE: For detailed operation procedures, refer to "Current Data Display For Engine". Ref. to ENGINE (DIAGNOSTICS) (H4DO) > 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 again.

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 SENSOR CONNECTOR .
1. Turn the ignition switch to OFF.
2. Disconnect the connectors from the ECM and battery current sensor.
3. Measure the resistance of the harness between ECM connector and battery current sensor connector.
  Connector & terminal
  
  (B135) No. 22 - (B472) No. 2:
  
  (B137) No. 11 - (B472) No. 3:
Is the resistance less than 1 Ω?

Yes: Go to 3 .

No: Repair the open circuit in the harness between ECM connector and battery current sensor connector.
CHECK HARNESS BETWEEN ECM AND BATTERY CURRENT SENSOR CONNECTOR .
Measure the resistance between ECM connector and chassis ground.

Connector & terminal

(B135) No. 22 - Chassis ground:

(B137) No. 11 - Chassis ground:

Is the resistance 1 MΩ or more?

Yes: Go to 4 .

No: Repair the short circuit to ground in the harness between ECM connector and battery current sensor connector.
CHECK FOR POOR CONTACT .
Check for poor contact between the ECM and battery current sensor connectors.

Is there poor contact of the ECM or battery current sensor connectors?

Yes: Repair any poor contact between the ECM and battery current sensor connectors.

No: Replace the battery current sensor. Ref. to STARTING/CHARGING SYSTEMS(H4DO) > BATTERY CURRENT & TEMPERATURE SENSOR .