Technical Car Experts Answers everything you need: car running lean

Saturday, January 19, 2013

Chrysler Van System Too Lean Bank 1

OBD Error Code P0171 On Chrysler Van

Chrysler Van will not Start

The starter turn over right but Engine will not start and Error code P0171 comes up.
n these case first see if you could hear the fuel pump turning ON when you crank/ start the engine.

Normally when you turn the key to start and start to Run you hear fuel pump running noise for 1-2 seconds.Hear that noise.If that fuel pump start noise is not heard then its fuel pump start up failure.

NOW why these code P0171 gets set:----

Engine running rich or Engine running Lean all is controlled by PCM.
The powertrain control module (PCM) has control and ability to watch the upstream oxygen sensors to know how rich or lean the engine is running. It has the ability to compensate for rich or lean conditions up to an extent. Suppose if the PCM detects Engine running lean, then in that condition it will start adding more and more fuel to try to bring it back to the correct range. It can add up to about 33% more fuel, and if it still can't bring the ratio back into the correct range then it will set this fault code. This could be a bad upstream oxygen sensor or MAP sensor, fuel quality issue, but in your case it was most likely caused by low fuel pressure.So first get the fuel pressure tested,these will help to confirm the problem.

As per our Auto garage repair experience ,With code P0171 set and you not hearing the pump run plus a no start condition is pointing to a likely fuel pump failure.
So first check fuel pressure,then check for power and ground at the pump connector while a helper cycles the key on and off or cranks the engine. If the pump does have power and ground but won't run then it will need to be replaced.If the pump has power but pressure is less then also pump is faulty.Also it can be faulty fuel pump relay,as power is not there.

The fuel pump relay is located in the box under the hood which you could try swapping with another and see if that helps but it's unlikely. Relays very seldom fail.

To measure the fuel pressure the simple procedure is as follows :--

Remove the fuel line from the rail and install a T hose inline and then attach the fuel pressure gauge to the T hose. There isn't a test port on the fuel rail itself on your Chrysler Van model.

Many a times confirming the fuel pump start up noise becomes very difficult.In that case take the help of helper.

As per Chrysler Van the pump connector is easily accessed, it clips up to the frame right behind the fuel tank located towards the center of the tank area.

With the chime going off when turning the key on it can be tough to hear the pump. It would be best to have a helper back near the tank or a helper turning the key while you listen back there.

For mode help and information regarding fuel pump connector ,There are four wires in the connector. The one to be checked are black/light green which is ground, and the fuel pump driver wire is dark blue/orange.

These details will help.
Thanks.

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