Navigate to the or Battery / Power Supply submenu.

: Voltages wildly fluctuating between 12.5V and 15.1V on the dashboard cluster live-data feed.

Less frequently, out-of-date ECM software or an internal voltage regulator fault within the alternator can manifest as this current loop error code. Step-by-Step Diagnostic and Repair Process

: Modern Nissans feature an "intelligent" battery sensor mounted directly on the negative battery terminal. If this sensor suffers internal failures, the ECM cannot get reliable data.

: The ECM analyzes data from this sensor. If the battery is fully charged, the ECM commands the alternator to drop its output voltage (sometimes down to 13.0V–13.3V). This decreases engine load, reducing fuel consumption and emissions.

When the ECM detects that the signal from this sensor is irrational, missing, or out of its calibrated operational bounds, it triggers P155B-00 to protect the electrical system. Common Symptoms of P155B-00

The Nissan P155B-00 code is a specific error code related to the throttle control system in Nissan vehicles. Understanding the causes, symptoms, and possible solutions for this code can help you diagnose and repair issues promptly. By taking preventative measures and addressing issues promptly, you can minimize the risk of triggering the P155B-00 code and ensure your vehicle runs smoothly and efficiently. If you're experiencing issues with your Nissan vehicle, consult a qualified mechanic for proper diagnosis and repair.

The P155B-00 is a generic manufacturer-specific code, but for Nissan, it is almost exclusively tied to the battery current sensor and its associated circuits. It’s important to note that this code is different from P1554 (which is also a battery current sensor code but with a different diagnostic priority) and other codes like P155E and P155F, which often need to be addressed first if they appear alongside P155B.

Multiple components work together in the Energy Management system. P155B-00 is usually caused by:

To help narrow down the exact troubleshooting steps for your vehicle, could you tell me: What is the exact of your Nissan?

A failure in an integrated circuit loop means several points of failure could be responsible:

: During acceleration, the alternator reduces its load or decouples from the engine entirely, leaving vehicle electrics to run temporarily off battery power to preserve fuel.

To properly resolve code P155B-00, technicians rely on standard physical and digital verification pathways. Step 1: Battery Health and Specification Check

The P155B-00 code is a manufacturer-specific code, which means it's unique to Nissan vehicles. This code is related to the throttle control system, specifically the throttle control actuator. The code indicates that the throttle control actuator has a problem with its control circuit.

: The car limits maximum engine RPM or speed to prevent component damage.

Occasionally, the ECM requires a software update to correct hyper-sensitive diagnostic thresholds for this specific circuit. Step-by-Step Diagnostic and Repair Process

In modern Nissan diesel engines (such as the 2.3L dCi found in the Navara or Terra), the VGT system uses an electronic actuator to adjust the vanes inside the turbocharger. This adjustment regulates the amount of boost pressure delivered to the engine based on load and speed. When the Engine Control Module (ECM) detects that the actual position of these vanes does not match the commanded position, it triggers the P155B-00 code. Common Symptoms When this code is stored, drivers typically experience: