P1551

P1551, P1552 BATTERY CURRENT SENSOR





Description
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 battery. 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 System Description.

CAUTION:
Do not connect the electrical component or the ground wire directly to the battery terminal. The connection causes the malfunction of the power generation voltage variable control, and then the battery discharge may occur.




DTC Logic

DTC DETECTION LOGIC

DTC DETECTION LOGIC:

DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 8 V with ignition switch ON
- GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON and wait at least 10 seconds.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES - Go to P1551.
NO - INSPECTION END




Diagnosis Procedure
1.CHECK GROUND CONNECTION
1. Turn ignition switch OFF.
2. Check ground connection M95. Refer to Ground Inspection in Circuit Inspection.
Is the inspection result normal?
YES - GO TO 2.
NO - Repair or replace ground connection.
2.CHECK BATTERY CURRENT SENSOR POWER SUPPLY CIRCUIT-I
1. Disconnect battery current sensor harness connector.
2. Turn ignition switch ON.
3. Check the voltage between battery current sensor harness connector and ground.





Is the inspection result normal?
YES - GO TO 9.
NO - GO TO 3.
3.CHECK BATTERY CURRENT SENSOR POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between battery current sensor harness connector and ECM harness connector.





Is the inspection result normal?
YES - GO TO 5.
NO - GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors F1, E3
- Harness for open between battery current sensor and ECM
- Repair open circuit.
5.CHECK SENSOR POWER SUPPLY CIRCUIT
Check harness for short to power and short to ground, between the following terminals.










Is the inspection result normal?
YES - GO TO 6.
NO - Repair short to ground or short to power in harness or connectors.
6.CHECK COMPONENTS
Check the following.
- Crankshaft position sensor (POS) (Refer to P0335.)
- Camshaft position sensor (PHASE) (bank 2) (Refer to P0340.)
- Exhaust valve timing control position sensor (bank 2) (Refer to P1078.)
- EVAP control system pressure sensor (Refer to P0451.)
- Refrigerant pressure sensor (Refer to Diagnosis Procedure.)
Is the inspection result normal?
YES - GO TO 7.
NO - Replace malfunctioning component.
7.CHECK APP SENSOR
Refer to P2122.
Is the inspection result normal?
YES - GO TO 14.
NO - GO TO 8.
8.REPLACE ACCELERATOR PEDAL ASSEMBLY
1. Replace accelerator pedal assembly.
2. Go to P2122.
- INSPECTION END
9.CHECK BATTERY CURRENT SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between battery current sensor harness connector and ECM harness connector.





4. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES - GO TO 11.
NO - GO TO 10.
10.DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors F1, E3
- Harness for open or short between battery current sensor and ECM
- Repair open circuit or short to ground or short to power in harness or connectors.
11.CHECK BATTERY CURRENT SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check the continuity between battery current sensor harness connector and ECM harness connector.





2. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES - GO TO 13.
NO - GO TO 12.
12.DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors F1, E3
- Harness for open or short between battery current sensor and ECM
- Repair open circuit or short to ground or short to power in harness or connectors.
13.CHECK BATTERY CURRENT SENSOR
Refer to P1551.
Is the inspection result normal?
YES - GO TO 14.
NO - Replace battery negative cable assembly.
14.CHECK INTERMITTENT INCIDENT
Refer to Intermittent Incident.
- INSPECTION END




Component Inspection
1.CHECK BATTERY CURRENT SENSOR
1. Turn ignition switch OFF.
2. Reconnect harness connectors disconnected.





3. Disconnect battery negative cable (1).
4. Install jumper cable (A) between battery negative terminal and body ground.
5. Turn ignition switch ON.
6. Check the voltage between ECM harness connector terminals under the following conditions.





Is the inspection result normal?
YES - INSPECTION END
NO - Replace battery negative cable assembly.