Yo fellas, I guess thats not the problem. The system needs all monitors checked, the temp not high enough statement is wrong, cause I tricked the ECU with the shorting of the sensor. Furthermore 70 (or even less) degrees would be enough to get ready.

 

The tricking of the ECU with a shorting clip on the ECT sensor connector may not be a valid test configuration

The resulting sensor value may be out of expected range and rejected

This ECU will do that on other sensors which may include the ECT and default to operating in a different way like a different set of data maps or arrays , as a not optimized limp mode

But your thinking makes sense if the ECU behaves like you think it would but not always the case

 

ive not had all my monitors checked ever.

emissions has never passed. There might be another, I can’t recall, but I believe catalyst has never passed either. Car runs fine. That’s not the problem.

 

Driven another cycle and checked with torque app. All monitors ready, except O2 sensors. O2 heater passed. Long fuel trim shows fluctuating volts when i hit the gas, short fuel trim is always at zero volts. Is that normal, when the engine is in open loop or is one O2 broken? But why is the O2 heating marked as complete?
Thanks fellas. :-D

 

Editing and thinking while I'm away on errons

 

Sorry, no clue. One of the two O2s broken isn't possible as they both show volatile voltage at LTFT and both the same.

 

The target is 0.0 % as a variable unit of measure and not a voltage signal

You can expect + 0r- 3.0 % in practice from reading other's post

This has to do with the size of increments of the injectors pulse widths and if the injectors are mechanically dragging

An example with numbers would be if you can regulate the pulse width in 1 / 100 th of a second or 1 / 1000 th of a second which would require a larger data array

A perfect pulse width and perfect resulting 0.0 % would require a large map or data array in the ECU

To interrupt the graph above .......

Editing

The heaters would have to have a current meter inside the ECU to have a true reading if the heaters are functioning

You can test the heaters outside the ECU and there is one fuse for all O2 sensors , there is a connector that has a history of corroding and is subject of a Jaguar TSB as this one wire for all sensors passes through

The more common bad reading is a negative STFT % as the mixture is too rich and there are solutions people have come up with in practice

Mine was a - 25.4 which is the furthest range the ELM 327 device will show , mine was a missing line to the EVAP valve connected under the intake manifold fwd of the throttle body butterfly and a cracked exhaust manifold

There are 2 coolant lines on the butterfly under there that can confuse things

There have been problems with the secondary air injection ( smog pump )

 

Hello guys, still no luck with my cat. Pulled the fan fuse "Nr. 11" to bring the temperature up. I get the same results (pictures). Only one fault code stored but this is a false alarm i guess. Swapped the O2 connectors again, still nothing changed. Added some water to the cooling system, nothing. New thermostat and temp-sensor. Nothing changes. I'm so sad. The car needs to go if I can't fix it soon. No spot to park it anymore. Screenshot states: open loop due to insufficiant engine temperature. short fuel trim zero changes, long fuel trim fixed. Volts 1,27 V at idle. Decrease when I hit the gas.

 

Isn't the car seeing coolant temp at 102C? That would indicate that its to temperature and that the car sees that.

You have replaced the oxygen sensors and the coolant temp sensor already, I believe?

Have you checked the pins on the ECU for corrosion? I don't recall if that was checked. I think there's something wrong with the ECU.

 

The ELM327 is reading the ECU and shows the102C, so I guess its OK. Yes, all replaced and OEM parts. No I haven't. Have to look where the ECU is. Thank you mate.

 

Assuming you're LHD, the ECU is in the passengers footwell. Pull the carpets back, and you'll see it. I think you'll need a 10mm deep socket to get it out. I can't believe we haven't thought of this sooner. There may be some corrosion causing these problems.

When you pull off the red and black harnesses, look for any kind of greenish corrosion. Also check the pins to make sure nothing is loose.

 

The 102 C is a good reading to be in closed loop

This is on the Red color ECU connector and is the connector side veiw market in purple and yellow sockets

look to ensure you have the 2 pinching tabs to each socket





O2 sensor heater fuse X and the pins on the ECU for the sensor hearers ( the ECU provides a ground ) , will have to look if there is a relay involved

EGR poppet clean

Secondary air pump ( smog pump ) running ? but in the time you get to 102 C you are past the operating cycle of the pump as whell as maybe the )2 sensors

But if you were driving and came to a stop sign and go back to idle the question is if the )2 sensor heater cycle back on ?

Smog pump air check valve sealing closed ?

Vaccuum leak check ?

Exhaust leak check ? this includes the 4 studs on the exhaust manifold down pipe / donut gasket area

Your MAF reading at idle should be a bit over 4.0 grams / sec at idle and it is common to have to multiply the ELM - 327 reading by a factor of 10 or 100 to correct a common flaw in the reader

Otherwise, a direct reading on the center wire at the MAF connector should read 1.2 volts DC at idle as a cross reference , this is very dependent on the correct idle speed

1.2 volts or close will tell you the MAF sensor is at least alive and being used by the ECU

Signs of the coils arcing on the valve cover walls ?

A clean engine block large ground strap attached to the starter mounting bolts helps

The valve cover is electrical isolated from the engine block in design with the shouldered isolators / bushings but in practice .................

 

Nevermind the coils and smog pump. Those will not affect your ability to go closed loop. I'm nor sure vacuum leaks could prevent this.

The ECU look for FOUR sensors before it allows you to go closed loop:

1. Coolant Temp Sensor must be above a certain temp. You have that.
2. MAF Sensor must provide expected values. You have that.
3. TPS must be within range. I don't know for sure if you have that. At idle, your "drosseln" must read at 12.9%, or very close. I see way above that it was reading 12.2%. I'm not sure that would be bad enough to fail the car from going closed loop.
4. Oxygen sensors. They must reach temperature within a certain timeframe and they must provide data within range. You said you replaced these, so I have to assume all is well with the oxygen sensors you installed, and I believe you only have two. The fact that nothing bad happens when you switch the two sensors (Post #68) makes me believe here lies your problem.

I had an issue once where the ECU was the problem. It just wouldn't read the oxygen sensors correctly, so they ran flat, instead of constantly flip flopping. Once I replaced the ECU, all was well.

The first thing we need to do, is check the pins on your ECU....after that, I'm afraid the best option would be to test with an alternate ECU which is not an easy task? I believe the x300 ECUs will work, but will show a security light on your dashboard, but it should work just fine. Perhaps that's what you can do....those ECUs tend to be easy to find and cheaper to buy,

 

Many thanks fellas! My car is a german spec one so no EGR and only 2 O2s. Pull the carpet back? I've seen a picture of an UK car and its right in front of the door speaker. Is that correct? How do I get the plastic cover away? Where do I have to pull please? I don't want to break it.

Throttle = Abs. Drosselklappenstellung = 0% So that means its much too low? (TPS)

New ECU is a problem because of the immobilizer. It has to match, I read that in another forum. The O2s show voltage at long trims, so the ECU is sending voltage to the O2s and can't be broken or am I wrong?

 

If you're TPS is at 0%, that's gonna be your problem. It shouldn't ever go below 12%. 12.9% is the correct idle mark. If it goes significantly lower than that, it is out of range and the car will not go into closed loop.

It is not a cheap part. There are no known alternatives, so its best to just bite the bullet and order it. Do not be tempted by a used part.

 

Oh nooooo. But the car idles perfect, also no problems when I hit the throttle. I resetted the ECU some weeks ago (shorting the battery cables). Maybe it needs to relearn?

 

That's not a thing on the AJ16 engine. It does nothing. The only way to reset the TPS is with a WDS/PDU, or some other diagnostic device that has Jaguar specific software.

Relearning means that 13.2% becomes the new idle position. 0% means something is terribly wrong. Maybe its not the sensor, but something isn't working right between the sensor and the ECU. Maybe try unplugging it, then plugging it back in while running, once it's hot, just be careful not to burn yourself.

You still haven't looked at the ECU pins....

 

I can't look at the pins. The car isn't here. Only on weekends. I read at google that 0% TPS is okay. Also I have no DTCs. My radio was resetted and maybe also the TPS (if its wrong). but why is the scanner statiing "engine temp". Makes not much sense to me.

Also 650 rpm is perfect. TPS wrong would mean 1000 idle or something.

The value was 12,2% now 0. Means it has been resetted. So some drive cycles and it should recalibrate?! Or the new ELM Scan is wrong.

 

Well if Google says it's ok, then it must be true.

I don't believe it is. I am not a Jaguar engineer, I have no qualifications other than owning one for 12 years. I own a PDU and a WDS. If my car's TPS had a 0%, I believe it is out of range. Your car remains in open loop, so perhaps since it's running off of programmed maps. I don't know the answer. A bad TPS does so many strange things on these cars. It seems to be one of the sensors that can bench test perfectly fine, yet cause so many problems in the car.

Start a new thread, ask others if they've ever seen a 0% from their TPS....hell, I'd be shocked if anyone saw anything below a 12.0%! 0% means the butterfly is fully closed, starving the engine of air. It would stall out for sure.

 

Yes, sure no offense! I am thankful but I need to understand this. Would love to get my hands on a PDU etc. but no chance. Buying? 2500 $ :-(

edit: Stall? not at all so the readout is wrong. 650 rpm looks like 12,xx%