Hello

I have a problem (Jag STR 2002) - I can not read the LTFT and STFT fuel adjustments for anything. I connected several interfaces, various programs including LPG driver are not able to read trims. Any scanner that connects it shows 0. I will get almost every module in the car, but these corrections are not read for anything - does anyone have any ideas why the kitten does not show it?
In addition, there are a few errors that always appear in the readings - I note that nothing suspicious happens with the car, no Check Engine or Restricted Performance, it drives, accelerates and theoretically everything is fine. Only such errors appear:

P0138 - HO2 Sensor sense circuit high voltage - bank 1, downstream (1/2)
P0400 - Exhaust Gas Recirculation Flow Malfunction - if the EGR did not work, would it rather Check by?
P1107 - MAP Sensor sense circuit low voltage - if MAP does not work, it probably would not drive properly because he would not see the compressor pressure, but according to the documentation if I understand correctly the computer then assumes the default value: ECM Default: - Default value 1.013 BAR (29.92 in hg) used
P1647 - ECM HO2 Sensor control malfunction - bank 2 upstream (2/1)

It looks quite serious errors but I did not notice anything disturbing in the engine's operation.

I will be grateful for tips on how to find these corrections and something about these errors.

 

Various codes mean the car cannot do fuel trims properly so first fix the faults.

 

I know that I need to fix these codes :-) I am just wondering the fact that these are quite important elements which according to the computer do not work or do not work properly and it seems to me that the engine should not work properly without an active MAP sensor. The engine works normally, the car accelerates without any problems and no errors or warnings on the dashboard. Getting to EGR or MAP is not easy in this car and I would not want to waste a whole day and by the way I have to change the seals that I have to take off on the way. It seems to me that even in spite of problems with setting the fuel mixture, the computer should show some values and in my case it shows only 0. The computer must see these values otherwise would throw out the Restricted Performance error? - the same applies to the boost pressure, and the MAP sensor is not functional?

In any case, I probably have to get it out because otherwise I will not check. I can only check and clean, possibly preventively replace the MAP, because I do not want to disassemble it twice.

update:
ok so P1647 points to oxygen sensor bank 2/1 so this may be the reason for the lack of fuel adjustments - I need to look at the wires whether they are damaged or replace the sensor. Does anyone know the number of this sensor will be faster and easier to find the right one?

 

Your reasoning may seem plausible but is not actually correct.

You can download - free - the information you need: workshop manual, codes PDFs, and of course Search will show you what others were advised and how they fixed the problems.

I'd be sure to check whether there might be any common cause especially if those codes occurred at about the same time.

 

Ok, I did a little research and the EGR and MAP error are connected because the MAP sensor circuit error also causes no EGR readings. I need to get to MAP or its plug and check it out. As for the oxygen sensor bank 2/1, here is nothing else but to check the wires or replace the sensor itself, because it is probably old and no one has looked there for long time. I did not pay any attention to it before, but after turning the key, the Check Engine light does not light up, especially that MAP, EGR and oxygen sensor errors cause for 100% (according to the manual) CE lihgt up. I did the instrument cluster test and the CE light does not light up at all. I conclude that these errors have already been around for some time and some idiot either solder out the diode or damage the path to it instead of removing the cause.

I have to wait a few weeks to look for the reason because now there is at paint shop - a bit of rust, some patches and painting some elements after meeting deer .

 

generic OBD II bluetooth adapter + torque on android

 

Ok, but why do I need it? I know this program, I tried it and it still does not show anything (STFT and LTFT is not change values - show only 0 at any interface and program I have access) . I have probably already identified the problem as I have already mentioned, I have to wait for the car to come back from the painter. I am more worried about what dumbass did to the dashboard to get rid of CE light. I will exchange oxygen sensors, check what happens to the MAP and pull out the instrument cluster to check what is done there.

 

You hail from Poland, I see. Does your country require full OBD II support? Or if so, perhaps the car was imported on the gray market from a country that has no such requirements.

I’m wondering if the car was originally delivered to a country that didn’t require OBD II. If so, and this is strictly conjecture on my part, the computer may have been programmed to always leave the light off.

 

Here you surprised me because I did not know that you can program such behavior of CEL. From what I know, the car had its first registration in Denmark, but if it can be programmed, then every next owner could do it, although I do not know why he would do it. Getting rid of such an important control is asking for problems. As soon as I pick up the car from the painter, I will remove the instrument cluster and see if there are any deliberate damage.

 

Will be waiting for your updates. I've never seen a (modern) car with so many codes and no CEL. The absence of trims is even more suspicious. Here is my 5 cents: http://www.jagrepair.com/images/Auto...r%20Rev2-1.pdf

 

dauraf thank you for the link - yes it is very suspicious that with such serious errors there is no CEL and what's more interesting, the car goes without a problem. My friend had a similar case in BMW (no STFT and LTFT readings) and it turned out that someone changed the modules from different cars and it was necessary to adapt them to make everything play together. It is possible that, for example, the ECM has been inappropriately substituted from another car?

 

Realistically, you can't do that.

 

It's not possible, realistically, no. You would have anti-theft.

Forget these wild fantasies. Go with normal fixes etc.

 

I'm finally updating. It took a while but a lot was happening at the car so there was no opportunity to take care of it. I was supposed to give the car to a paint shop but the week before I had a close encounter with wildlife :-). Grill, headlight, bonnet, fender, front belt and some other small parts. Later painting and another 2 months :-). As I started with the oxygen sensor and map sensor, the supercharger has broken down, or at least I thought so - long story short: don't replace the supercharger when the ignition coil fails :-). Oxygen sensor replaced - of course only Denso, do not try the substitutes because they do not work :-), map sensor replaced. Fuel trims are back, boost pressure also, no errors. Subject to close. End of story :-).

 

Great for your repair success....sorry to hear about the wildlife incident.....hope your car gets fixed quick so you can enjoy the throttle again

 

The cat is already repaired :-). The order was - wildlife, paint shop, oxygen sensor first approach with replacements, replacement of the supercharger, of course, it was not necessary: P, replacement of the MAP sensor, replacement of the ignition coil and finally the proper oxygen sensors from Denso :-). I learned a lot about how these systems work, I lost a lot of money but I did everything myself, so I'm generally happy :-)

 

A little late to the party but I would have said that the o2 sensor reads the fuel mixture which determines the trims. If they are dead, wid think there were be a default table it uses for fuel trims so maybe thats why there wasnt a reading

 

Or it operates open loop with all the problems of that (and of course no useful readings).