2008年2月8日 · Check ALL vacuum lines (some are pressure), and check the boost line inside the ECU. How to remove the ECU. What to look for, inside the ECU, is a short peice of vacuum tubing. This tube tends to rot and leak, producing a no or low boost code. No hose inside/to the ECU on an ALH. All lines are vacuum. Definitely check/change the vacuum lines.

2017年1月1日 · EOBD II Error Code: P1556 Fault Location: Charge Pressure Control - Negative Deviation Possible Cause: Reduced power output. Limp mode. Limp mode: What is it, what are the causes, and how to fix it for the Audi and VW TDI diesel turbo. Boost Pressure too Low. Hoses/Pipes incorrectly connected, disconnected or leaking. Charger Pressure Control ...

The P1556 code for Volkswagen vehicles indicates a charge pressure negative deviation. This means that there is an issue with the turbocharger system, specifically with the boost pressure being lower than expected. The turbocharger is responsible for increasing engine power by forcing more air into the combustion chamber.

The fault code P1556 can be caused by an external leak on the intake or exhaust side, a faulty charge air pressure sensor, a faulty wastegate regulator valve, or a faulty turbocharger. Do you know you can clear most fault codes —but some could mean serious danger?

2025年1月13日 · What does P1556 mean? P1556 indicates that there is a negative deviation in charge pressure control, meaning actual boost pressure is lower than expected. What causes P1556? P1556 can be caused by faulty vacuum hoses, a malfunctioning N75 valve, or issues with the turbocharger itself. Can I drive my car with a P1556 code?

17964/P1556 - Charge Pressure Control: Negative Deviation Possible Symptoms. Reduced power output; Limp mode; Possible Causes. Boost Pressure too Low; Hoses/Pipes incorrect connected, disconnected or leaking; Charger Pressure Control defective VNT (variable nozzle turbo): nozzles stuck; Solenoid Valve for Boost Pressure Control (N75) defective ...

2019年8月30日 · Repair Information for P1556 code. Learn what Charge Pressure Negative Deviation means, location and how to repair?

2022年8月15日 · Hey guys I have a 2002 Jetta TDI 5 speed. that will go into limp mode when trying to go up a hill and on flat ground I have very poor acceleration and associated with a loud rushing noise under acceleration. I have pressure tested the boost system and there is no leaks.

2016年6月16日 · I drive a 2001 VW New Beetle 1.9L TDI. So around May 2016 my car went into limp mode and within a couple days a check engine light came on. I ran the code and I found it to be P1556. I looked that up and it turned out to mean something with my turbo is bad.

Negative deviation could be caused by a charge air leak or a bad waste gate in the turbo. I would suggest you first check all the hoses from the turbo to the intake including the innercooler. If you dont have any leaks then you need to check the vacuum lines that go from the waist gate to the change over valve.