Nissan P155b-00 New! -

Code Meaning: P155B-00

• Description: This code is associated with issues related to the Electric Throttle Control (ETC) system, particularly problems with the throttle valve's opening angle, or there might be a fault in the way the throttle valve operates.

Code Definition

P155B-00: ECM (Engine Control Module) / Intelligent Power Module (IPM) / EV/HEV System — often related to a "Current Sensor Circuit Range/Performance" or "Motor Control System" error. nissan p155b-00

In many Nissan applications (especially hybrids like the Pathfinder Hybrid, Infiniti QX60 Hybrid, or some newer e-POWER models), this code points to an issue with the motor/generator current sensor inside the IPM (Intelligent Power Module or inverter). Code Meaning: P155B-00

Step 5 – ECM Command Test (Active Test)

• Using a bidirectional scan tool, command the actuator from 0% to 100% while observing actual position response.
• If commanded position does not match actual, suspect actuator or mechanical binding.

5. Diagnostic Procedure

Repair Steps:

1. Clean or Replace Throttle Valve: If the throttle valve is dirty, cleaning it might resolve the issue. If faulty, it needs to be replaced.
2. Repair or Replace Wiring: Damaged wiring needs to be repaired or replaced.
3. Replace Throttle Valve Control Module: If diagnosed as faulty, it should be replaced.
4. ECU Update or Replacement: If the issue lies with the ECU, it might need a software update or replacement.

Diagnostic Steps:

1. Scan for Codes: Use a scan tool to confirm the presence of the P155B-00 code and to check for any other codes.
2. Inspect Throttle Valve and Connections: Visually inspect the throttle valve, its control module, and the wiring for obvious signs of damage or wear.
3. Check Voltage: Measure voltage at the throttle valve control module to ensure it is receiving proper power.
4. Consult Technical Service Bulletins (TSBs): Nissan may have issued TSBs related to this code.

Frequently Asked Questions (FAQ)

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. Description: This code is associated with issues related

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.

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.

Likely Causes

1. Faulty IPM / Inverter assembly (internal current sensor failure)
2. Wiring harness issues between IPM and ECM (corrosion, bent pins, loose connection)
3. ECM software glitch (rare; may require reprogramming)
4. 12V battery or DC-DC converter instability (on hybrids)