The Nissan fault code P155B-00 indicates a range/performance issue with the Variable Geometry Turbocharger (VGT) Actuator. Specifically, the engine control module (ECM) detects that the turbocharger vanes are not moving to the commanded position or are moving too slowly. Limp Mode: Significant loss of power or RPM restriction. Hesitation: Poor throttle response during acceleration.
Warning Lights: "Check Engine" or "Drivetrain Malfunction" alerts. Smoke: Excessive black smoke from the exhaust under load. Common Causes
Soot Buildup: Carbon deposits jamming the internal turbo vanes (most common in diesels).
Faulty Actuator: Internal electronic failure of the turbo control motor.
Wiring Issues: Corroded or frayed wires in the harness connecting the actuator to the ECM. nissan p155b-00
Vacuum Leaks: (On older vacuum-actuated models) cracked or disconnected vacuum lines. Troubleshooting & Fixes 1. Visual & Manual Inspection
Check Linkage: Inspect the rod between the actuator and the turbo. Ensure it moves freely and isn't bent.
Inspect Wiring: Look for "green corrosion" in the actuator plug or melted insulation near hot exhaust parts. 2. Basic Cleaning
Turbo Cleaning: In some cases, specialized "VGT cleaner" can be used to break down soot without removing the turbo. The Nissan fault code P155B-00 indicates a range/performance
Clear Codes: Use an OBD-II scanner to clear the code and see if it returns immediately after a test drive.
Code Meaning: P155B-00
Q: Will P155B-00 clear itself? A: Unlikely. Even if the valve temporarily frees itself, the code will remain in the ECM until cleared with a scan tool. The condition usually recurs quickly.
Q: Can a bad thermostat cause P155B-00? A: No. The code specifically targets the bypass valve, not the main thermostat. However, replacing both components together is often good preventative maintenance. Description: This code is associated with issues related
Q: Does P155B-00 affect emissions testing? A: Yes. In most states, a check engine light with an active DTC is an automatic fail on the OBD-II emissions test.
Q: My Nissan has P155B-00 but runs fine. Do I still need to fix it? A: Yes. The valve can fail fully closed at any moment, leading to sudden overheating. It is not a benign code.
P155B-00 – Electric Intake Valve Control Actuator Circuit Range/Performance (Bank 1)
This code indicates that the Engine Control Module (ECM) has detected a performance issue or an out-of-range condition in the electric intake valve control actuator circuit for Bank 1. Unlike traditional oil-pressure-driven VVT, some Nissan models use an electric motor-driven actuator for continuous valve lift/timing control (e.g., on MR20DD, QR25DE, or VQ series with electric VVT).