Poor engine starting performance, excessive engine knocking at idle, engine runs in emergency mode.
If the above problem is raised, it could have several causes. Implausible values may cause the symptoms described. In addition, the following error codes may be stored in the engine control unit:
- P1556 – Turbocharging pressure, control limit is not reached.
In this case, proceed as follows:
- Disconnect wire harness multi-plug from the engine control unit and the coolant temperature sensor and perform a continuity test.
- Check contacts on both sides for corrosion and mechanical damage, repair if necessary.
- Check the ground connections.
- Check that the coolant temperature sensor functions perfectly. At 80 °C, the sensor should have a resistance of 275 - of 375 ohms. If the sensor is defective, it must be replaced.
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