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(TA248-1000) MIL and failure code P2452 (9-3) or P1908 (9-5)

TECHNICAL ADVICE - Quick information for your help
Bulletin Nbr: TA248-1000
Date: ........... February 2010
Market: All
MIL and failure code P2452 (9-3) or P1908 (9-5)

VEHICLES CONCERNED

Saab 9-3 and 9-5 with 1.9 DT/DTH diesel engines.

BACKGROUND

Failure mode causing MIL (Malfunction Indication Lamp) and failure DTC P2452 ( 9-3) or P1908 (9-5).

Due to the long and extreme cold period there is a risk for ice build up in the hose for the pressure sensor to the DPF (Diesel Particle Filter).

Warm particle trap fumes are transferred through the cold hose pipe which can cause water to condense and ice to build up.


If the hose between the DPF and the pressure sensor is blocked then MIL will come on and a DTC will be set.

CONDITIONS

Driving in combination with cold weather.

SYMPTOM DESCRIPTION

MIL and failure code P2452 (9-3) or P1908 (9-5).

ACTION

When the above symptoms have been identified, this problem can easily be checked with Tech 2 instrument following these menus: F0 Engine => Engine management system => F1 read values => Pressure in particle filter .

Check the pressure in idle on warm engine (should be below 1 KPa for empty trap)

If the engine is revved to approx 3000 RPM the back pressure should increase up to 5 kpa (with empty trap)

The pressure levels might vary but the importance is that the pressure increase during rev up indicating the pressure hose-pipe to be open to the sensor.

Note : The sensor itself is normally ok and most warranty returns support this

If the pressure does not rise then loosen the hose between the sensor and the DPF, at the particle filter end and clean the pressure hose-pipe with compressed air. A heat air gun might be needed if the flow is still blocked by ice.

Note: The regeneration process itself needs a warm engine to start.

Please inform the drivers and owners about performing short distance driving cycles since this can cause the particle filter to be overfilled and blocked.

Important !

Due to the risk of engine damage ensure the oil level is not overfilled. This is particularly important when carrying out a manual regeneration.