Nissan P155b-00 [portable] -

The master computer is not communicating correctly with the module. Diagnosis and Troubleshooting

Inspect the high-voltage (usually orange) wiring harnesses for damage, chafing, or exposed wires.

Check the lower grille area for any debris. Even a small pebble can jam the plastic vanes and prevent them from cycling. nissan p155b-00

Damaged wiring harness or loose connector near the front bumper. Visual Inspection (The "Free" Fix)

To understand the fault, one must understand the component. Modern Nissans utilize an attached to the negative battery terminal. The master computer is not communicating correctly with

Before condemning the sensor, the battery must be tested. If the battery is failing, the sensor code may be a symptom, not the cause.

Understanding Nissan DTC P155B-00: The Intelligent Battery Sensor Dilemma Even a small pebble can jam the plastic

In some Nissan service bulletins, merely replacing the sensor isn't enough. The PCM may need a software update to prevent the code from returning, specifically on 2013-2015 Altima models.