The Engine Management Light on my Octavia II 2006 is back on again. It comes on for a couple of days then goes off only to re-appear again 2/3 days later with a slight loss of power each time.

A diagnostics check shows the following fault:

17964 Charge Pressure Control

P1556-35-10 Negative Deviation-Inter

Anyone have any idea as to what this refers to, and what the fix is?

Regards,

Mbp

Well it could be anything to do with controlling the boost pressure

1. Wastegate fault

2. Mainfold leak

3. Boost pressure regulator

Autodata lists this a a common fault, don't know whether this is your problem but here it is

Known fixes and bulletins

Known fix

Affected vehicles

• All models.
  

Problem

• Poor starting.
  
• Excessive Diesel knock at idle.
  
• Engine runs in limp home mode.
  
• Trouble codes stored in engine control module (ECM) fault memory: P1556 - turbocharger (TC) boost pressure, control limit not reached.
  

Cause

• Engine coolant temperature (ECT) sensor transmits false signal.
  

Remedy

• Replace engine coolant temperature (ECT) sensor