Good afternoon Everybody.
I just would like to ask you if anybody knows what are the conditions on why the PCM from dodge caliber 07 (2.0) will force the system to open loop mode (actually it is displaying in my OBDII scanner "Open Loop Driving). My problem is on idle the car runs good (closed loop), however, as soon as I start pressing the gas pedal the
PCM switches to open loop mode, even during parking at pressing the pedal. The gas mileage is very low and the car doesn't have a good power. I mean, because the car is running most of the time at open loop, the car is running too rich and the PCM is not compensating nothing, so the stoichiometric ratio is really bad (commanded fuel ratio 0.730).
I checked the ECT sensor and it is measuring the temperature correct and it is not jumping back and forth, I mean it keep linearity.
I also cheched the O2 sensor (upstream) and it seems to be working properly. It is fluctuating between 0.1 and 0.9 V, however, when the PCM switches to open loop it stays at 0.9V, same as the sensor 2 (downstream sensor). Actually I interchange the two O2 sensors to see if the #1 was lazy, however, the #2 reacted at the same way.
I read that the three conditions to force the PCM to open loop are:
1. ECT reading
2. Timer after turned on the engine
3. O2 upstream sensor fluctuations (changing in a sinusoidal wave).

Is there any other sensor or condition that forces the PCM to return to open loop once it is in closed loop after pressing the gas pedal?
Note: I am getting a misfire code P0300 and P0301, and I am thinking that those are due a contaminated system because the engine has been running under a rich condition for a long time. What are your thoughts?
I also replaced the two VVT solenoids.
Of course some day I also replaced the spark plugs for new ones.

Everything without having any improvement yet.
Thanks in advanced for your support and Best Regards,
I also tried swapping the coil on plug between cylinders and the same thing with the injectors.

 

wide open throttle will cause an open loop condition.
any misfire condition makes the fuel trim adjustment meaningless; hence the open loop...correct the misfire condition.

 

Thanks Primem.
Question: Do you mean a misfire code will force the PCM switching to open loop? or are you recommending me to try fixing first the misfire issue instead of thinking the misfiring is due to the open loop condition?
Just as a double check, what I am getting is as follow: Turn on the car, after some seconds (of course at good warm temperature) the PCM shows closed loop, while in idle (in parking or drive) it will stay in Closed loop. However, when I press the gas pedal (in idle or drive) after some seconds the PCM switches to open loop (fuel trims at zero, oxygen sensor readings at 0.930V both sensors Upstream and downstream, commanded equivalence ratio of 0.730) and it will stay in open loop while i am driving. The only way the PCM returns to closed loop is after some seconds of not acceleration usually when I stop in a light. But again, once I speed up a little bit it switches again to open loop.

I will appreciate if you can give me some more feedback on what could be going on with my Caliber 07.

Thanks.

 

Do you have a misfire condition. Does it occur all the time or only during acceleration. if you have a misfire present, fix it before doing anything else.


misfire conditions skew 02 sensor readings and fuel trim readings so viewing them during a misfire condition will lead you astray. when a vehicle goes into open loop it ignores 02 data and runs on fixed programming based on ect, rpm and tps.