P1554

P1554 BATTERY CURRENT SENSOR




Component 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 (1) 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 Starting and Charging.

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.




On Board Diagnosis Logic
The MIL will not light up for this self-diagnosis.

NOTE: If DTC P1554 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643. Refer to EC-292. P0643

Overall Function Check
Use this procedure to check the overall function of the battery current sensor circuit. During this check, a 1st trip DTC might not be confirmed.

TESTING CONDITION:
- Before performing the following procedure, confirm that battery voltage is more than 12.8 V at idle.
- Before performing the following procedure, confirm that all load switches and A/C switch are turned OFF.

WITH CONSULT-III
1. Start engine and let it idle.
2. Select "BAT CUR SEN" in "DATA MONITOR" mode with CONSULT-III.
3. Check "BAT CUR SEN" indication for 10 seconds. "BAT CUR SEN" should be above 2,300 mV at least once.
4. If NG, go to "Diagnostic Procedure" below.

WITH GST
1. Start engine and let it idle.




2. Check voltage between ECM terminal 71 (battery current sensor signal) and ground for 10 seconds.
The voltage should be above 2.3 V at least once.

3. If NG, go to "Diagnostic Procedure" below.

Step 1-3:

Step 3 (Continued)-9:

Diagnostic Procedure

Component Inspection

BATTERY CURRENT SENSOR
1. Reconnect harness connectors disconnected.




2. Disconnect battery negative cable (1).
3. Install jumper cable (A) 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.