2019 Infiniti M35 V6-3.5L (VQ35HR) Diagnostic and Repair Information Page 649
3. Disconnect battery negative cable (1).
Black arrow: To body ground
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.
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, See: Starting and Charging/Charging System/Description and Operation.
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 battery discharge may occur.
