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P1549

Read the instructions below then start the fault diagnostic procedure.

Symptom: CHECK ENGINE. Engine weak.

P1549


Charge Air. Malfunction





Fault symptoms


• CHECK ENGINE.

• Engine weak.


On-Board Diagnostics

Type of diagnosis:


- Continuous. But interrupted when fault criteria fulfilled and will not restart until next driving cycle.


Enable criteria:


- General conditions for this trouble code: When starting the engine, the atmospheric pressure must exceed 78 kPa and the engine coolant and intake air temperatures must exceed -7°C.

- Test 1: Charge air control regulating air mass per combustion.

- Test 2: Throttle control regulating air mass per combustion.


Fault criteria:


- Test 1: Current air mass per combustion is 100 mg/c higher than requested. Charge air control valve PWM has dropped to lowest possible.

- Test 2: Charge air pressure exceeding 200 kPa. Throttle position reduced more than permitted.


Dependents:


- P0100, P0102, P0103, P0112, P0113, P1105, P1106, P1107 and P1108.


System reaction to a fault:


- Air mass per combustion limited to 600 mg/c.




OK report:


- Engine running for more than 60 s. Charge air control valve PWM has exceeded 10% on one occasion. Engine speed higher than 2500 rpm. Charge air control governing air mass per combustion. Current air mass per combustion differs with more than 50 mg/c from the requested. Or, Engine running for more than 60 s. Charge air control valve PWM has exceeded 10% on one occasion. Engine speed 1000-2000 rpm. Requested air mass per combustion exceeding 650 mg/c. Throttle control governing air mass per combustion. Charge air pressure below 160 kPa. Current air mass per combustion differs with less than 50 mg/c from the requested.


Fault handling: (See “Fault diagnosis, general” for more information.)


- Type III.


Diagnostic help

Fault diagnosis starts by inspecting the three charge air control valve hoses. Then, the basic engine and turbo are checked. If no defects are found then the charge air control valve is changed.

Functions in the diagnostic tool related to the fault:


• Diagnostic status for the diagnosis.

• Activate output for charge air control valve.

• Charge air pressure.


See also the description of readings in ”Fault diagnosis, general” for more information.