FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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Fault Conditions



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 condition for this diagnostic trouble code: Atmospheric pressure must exceed 72 kPa as well as coolant and intake air temperature must exceed -7 degree 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 longer than 60 sec. Charge air control valve PWM has exceeded 10 % on one occasion. Engine speed above 2500 rpm. Charge air control governing air mass per combustion. Current air mass per combustion differs less than 50 mg/c from requested. Or. Engine running for longer than 60 sec. Charge air control valve PWM has exceeded 10 % on one occasion. Engine speed 2000 - 3500 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 less than 50 mg/c from requested.

Fault handling: (For more information, Fault Handling III, Other Emission-Related Components and Function)

- 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.

For more information, refer to scan tool testing. Menu Read Values

Proceed to Diagnostic Procedures Checking Air Hoses