P1551
P1551, P1552 Battery Current SensorComponent 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.
CAUTION: Never 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.
On Board Diagnosis Logic
The MIL will not illuminate for this diagnosis.
NOTE: If DTC P1551 or P1552 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643. P0643
P1551-P1552:
DTC Confirmation Procedure
NOTE: If DTC Confirmation Procedure has been previously conducted, always perform the following before conducting the next step.
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
1. Turn ignition switch ON and wait at least 10 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to [P1551, P1552 Battery Current Sensor].
Diagnosis Procedure
Step 1-2:
Step 3-9:
Component Inspection
BATTERY CURRENT SENSOR
1. Reconnect harness connectors disconnected.
2. Disconnect battery negative cable.
3. Install jumper cable between battery negative terminal and body ground.
4. Turn ignition switch ON.
5. Check voltage between ECM terminal 71 (battery current sensor signal) and ground.
Voltage: Approximately 2.5 V
6. If NG, replace battery negative cable assembly.