I hope this rings a bell with someone: I have a 2009 LR2 with the gas L6 engine and 162k miles.

I replaced my electronic throttle body because... well it failed... and threw the appropriate codes for that. I installed a new one, and went for a drive about a half hour away. The truck ran great. I parked it for about 45 minutes, and it started fine, and drove home fine. The next day it started fine, but when I pulled out of the driveway it was "shuddering" from the motor running rough. It was very similar to a missing cylinder. It would shudder when accelerating, but smooth out when not under load.

I pulled back into the driveway, and got the codes:
P0108- Manifold Absolute Pressure/Barometric Pressure High
P0069- Manifold Absolute Pressure – Barometric Pressure Correlation

This seemed like good news, because the connector to the MAP sensor no longer has its clips, and so I figured it just fell off. When I checked it, it was a bit loose. So I used the gasket sealer trick... a blob of the stuff on the side and it holds the clip on. But nope, still threw the code. My next suspicion was that I had broken the MAP sensor, as it sticks out, and you have to finagle the manifold in and out. Sure enough, it was flopping around a bit when I checked it. And as I took it out, the tube broke off (luckily you can unplug and remove these from under the truck). I could see that it had been partly broken before I finished it off taking it out. This seemed like a promising cause, as an air leak right by the sensor would fool it, I think. So I very carefully crazy glued the tube on, roughed up the plastic on the tube and sensor body, and plastic epoxied the tube to the sensor body. I am 99% certain I didn't get any epoxy into the tube or sensor, as the tube was tightly glued with a small amount of crazy glue first.



Tube of MAP sensor epoxied back on

OK you guessed why I am here: It still runs rough, and still throws those two codes. One other odd symptom: The back-lights on the LCD screens of the dash and radio gently pulsate. This goes away when the engine smooths out. So here are my guesses at this point:

1) The MAP sensor is bad. It either got damaged internally when the tube cracked, or when I glued it, or while the tube was partially cracked off.
2) The wiring to the sensor is broken internally.
3) It has nothing to do with this sensor, but some other thing got left off by me, or pinched or shorted, and it messes with the manifold vacuum or the wiring to another sensor. But I went over and over all the connectors and believe I got them all: The connector for the throttle body; the tube and wire-bailed connector above it; the two sensors on the updraft part of the manifold; and the mass air sensor on the air intake tube.

So that's the deal. I'm going to swing for a new MAP sensor (was going to at some point anyway, so not to "trust" the epoxy fix). But meanwhile I wanted to shoot this past everyone, in case something occurs to someone that has not occurred to me. Has anyone had a problem that is related to this, that also causes the shuddering/rough engine, and the flickering LCD screen lights? Has anyone had these symptoms from a dead MAP sensor or wiring?

Any help is greatly appreciated.

 

1. Was the vehicle re-programmed to recognize the new throttle body? I'm pretty sure you have to do that or it will not recognize it. Need special software for that, or a shop that has the software, or the dealer.

2. I'd definitely replace the MAP regardless, not sure if it has to be programmed too but those things are sensitive.

 

I am also of the impression that you may have to re-program it to also recognize the new MAP sensor when replaced(hope I am wrong)? Subbed for further interest.

 

Thank you Merlin and Thor:

1) OK then I'll look into the procedure to re-program for the throttle body. I was under the assumption that, like the transmission shifting... which I think, like my daughter's Volvo... would "learn" from the driving habits, but I never looked into it. And her Tiguan does have a method to "teach" the car... calibrate... the new throttle pedal I installed. Some proceedure like pressing all the way to the floor, letting up, or like that... I forgot. Hopefully there is something like that, I'd HATE to have to pay the dealer for this. But I'll look into this, it is a good point.

2) On the MAP sensor... I'll order one right now. Should have done that last night. I did wonder if there was a calibration issue here, too, as you guys have. Maybe it will even sort itself out, after my affixing the tube to it? Like "relearn" for the fixed part, when it was running with it leaking? I don't think a couple of local trips will hurt the engine... If I keep it revving above about 2500 it smooths out. Anyway, for $77, I was being stupid not to just order one right away. A guy in Florida has them for $77, new Rover OEM (FoMoCo branded).

I'll post if I learn anything, and/or when I get the new part and install it, in a couple of days.

Thank you for your thoughts and feedback on the matter...

proto57

 

OK an answer on the need to relearn/reprogram/calibrate the throttle body and/or accelerator on the 2008-2011 I6 gas engine LR2's, from the official manual:

"The ECM performs a self test and a calibration routine on the throttle disc position at each ignition cycle. This is achieved by the ECM powering the damper motor to fully close the throttle disc and then fully open the throttle disc."

Yes! So thank god no need to relearn this, it re-calibrates each time you start the vehicle. Before I looked in the manual, I did an internet search for this. It seems that for other models of Land and Range Rover, yes it is necessary to reset/relearn/re-calibrate the computer for a new throttle body. For instance, for the "GEMS" engines, you need to reset computer to know the idle stop position:

https://www.roverparts.com/resources...osition-reset/

But those are different years, and different engines. Yes that site does list almost every model of Land/Range Rover, including all LR2's. But that list contradicts the video, and is probably there for other functions that this reader addresses. And I checked a few other reader/reset devices, including the specific iCar model for LR, and none I see list a reset/relearn function for the I6 gas LR2 (although they list that function for other models).

So it seems we are out of the woods on this... and I went into detail for others who may come across this thread, having replaced their throttle body and want to know. As for the my new MAP sensor, I ordered it, and should have it by the end of the week.

 

For the sake of completeness, I'll copy the official LR manual's descriptions of the operation of the Throttle Body, MAP sensor, and Throttle Position Sensors. If this is not allowed, my apologies, and of course delete this post:

Manifold Absolute Pressure (MAP) Sensor

The MAP sensor is located in the lower part of the intake manifold. The MAP sensor measures the absolute pressure in the
intake manifold. The sensor is a semi-conductor type sensor which responds to pressure acting on a membrane within the
sensor, altering the output voltage. The sensor receives a 5V reference voltage and a ground from the ECM and returns a
signal of between 0.5 - 4.5V to the ECM. A low pressure returns a low voltage signal to the ECM and a high pressure
returns a high voltage.

The MAP sensor detects quick pressure changes in the intake manifold after the electric throttle. The signal is used in
conjunction with the MAF sensor signal to calculate the injection period.
The ECM monitors the engine MAP sensor for faults and can store fault related codes. These can be retrieved using a Land
Rover approved diagnostic system. If the sensor fails, the ECM uses the MAF/IAT sensor signal value as a substitute.

Electric Throttle

The electric throttle is located at the entrance of the intake manifold and is secured to the manifold with four Torx head
bolts. The throttle also provides for the connection of the air cleaner housing outlet pipe which is secured to the throttle
body with a clip.

The electric throttle comprises the throttle body, a round throttle disc which is actuated by a damper motor and a throttle
position sensor. The electric throttle is controlled by the ECM and receives positional signals from the TP sensor. If a
failure of the motor occurs, the throttle disc is returned to its closed position by the springs, with limited engine speed
available to the driver.

Spindle Damper Motor [motor in the electric throttle body]

The motor is a DC damper motor which drives a gear wheel and two springs; one for opening and one for closing. The
motor rotates the spindle to which the throttle disc is attached. PWM signals from the ECM control the damper motor to
adjust the position of the throttle disc, regulating the amount of air entering the inlet manifold for combustion.

Movement of the motor is achieved by changing the polarity of the power supply to the DC motor, allowing it to be
operated in both directions. The throttle disc and the motor has two maximum positions; throttle disc closed which allows
minimal air flow through the electric throttle into the intake manifold and throttle disc open which allows maximum air flow into the intake manifold.

Throttle Position (TP) Sensor

The TP sensor is housed in the electric throttle assembly and is used to check the position of the throttle disc. Two
permanent magnets in the sensor connected to the throttle disc affect two Hall effect sensors. As the spindle is rotated
the magnets rotate around the Hall effect sensors and produce offset analogue signals back to the ECM. The ECM
compares these signals to stored values to ensure that they show an accurate throttle disc position. The offset signals are
that one Hall effect sensor produces a higher voltage as the throttle angle increases and the other sensor produces a
lower voltage as the throttle angle increases.

The ECM performs a self test and a calibration routine on the throttle disc position at each ignition cycle. This is achieved
by the ECM powering the damper motor to fully close the throttle disc and then fully open the throttle disc.

The ECM monitors the DC damper motor and the TP sensor for faults and can store fault related codes. These can be
retrieved using a Land Rover approved diagnostic system.

Accelerator Pedal Position (APP) Sensor

The APP sensor is located on the accelerator pedal. The sensor comprises a plastic housing which contains two
potentiometers and an analogue/digital converter. The potentiometers are connected to a common shaft which is actuated
by movement of the accelerator pedal.

The APP sensor provides the ECM and the CJB with information relating to the position of the accelerator pedal. The ECM
uses this information to actuate the damper motor in the electric throttle assembly to move the throttle disc to the correct
angle in relation to the pedal position.

The APP sensor receives a fused 12V supply from the CJB, which is controlled by the ignition relay in the BJB. The CJB also
provides the sensor with a ground. The sensor provides two outputs; the analogue output is transmitted directly to the
CJB, which in turn issues the signal to the ECM on the CAN bus, the second output is the Pulse Width Modulation (PWM)
signal which is transmitted directly to the ECM. Both the analogue and PWM signals transmit the same positional
information.

The ECM uses the PWM signal to calculate the required position of the electric throttle disc in the electric throttle. In the
event of a failure of the PWM signal, the ECM uses the analogue signal received from the CJB as a replacement. If the
analogue signal is also incorrect or missing, the ECM limits the maximum engine speed to 2000 rpm.
The PWM and the analogue signal are used for diagnosing faults with the APP sensor. If the ECM detects a difference
between the analogue and PWM signals a fault code is stored. The ECM will use the signal with the lowest value for
electric throttle control. The APP sensor position and any stored fault codes can be read using a Land Rover approved
diagnostic system.

 

The issue we are referring to is not one of re-learning or re-calibrating.

Rather it is an issue of the vehicle recognizing and communicating with the new parts. Many other parts on this vehicle require that programming. Hopefully that's not required for the TB and MAP.

IIRC the vehicle will start and drive without the MAP even being plugged in, it just won't drive very well.

 

The new MAP sensor came on Monday (two days ago). I installed it, and drove a total of maybe two hours since then. The problems are still there: Bucking on acceleration between about 1500 and 2000 RPM, and still throwing the same codes. But now I do notice that the problem is intermittent, in that there were periods of time running when the problem was completely gone... where I had smooth running, no bucking, and smooth acceleration. The truck would run like that maybe 5 miles or so, then it would start up again.

Well whether it amounts to recognizing and communicating, or calibration (as throttle bodies and pedals are)... I mean, however some and different sensors and controls are recognized by the vehicle's computer, it seems the MAP sensor and throttle body do not need any special programming. I did outline my reasons for not believing this is the case, but since it was brought up again, I double checked the official workshop manual on this issue. I did a complete search of the manual, and read and re-read the sections on the MAP sensor and throttle body installations, and the related error codes, and even words like "program" and "programming".

On the LR2 gas I6 engines, I can say with confidence this is not required. It seems the sort of systems that do need programming relate to the adjusting headlamps, locks, seats, and a dozen other parameters.. such as whether and when the doors lock automatically and so on. I could find no need for programming for any new parts in engine control management, or transmission, and so on. They would of course have such needs and procedures in the factory manual, so this is not a/the problem with these parts and the poor running.

Anyway, since I still do have the problem, here are some ideas:

1) It is the wiring to the MAP sensor. There is an internal fault in the connector, or the wiring (a break inside the insulator of the wire?). This is supported by the intermittent nature of the problem, I think, as we all have experienced broken wires making intermittent contact, which then makes problems come and go.

2) An air intake leak after the MAS sensor: Again we all have experience manifold leaks. They usually... well in simpler vehicles in the past... cause "loping idle". But I note that some other MAP codes list air leak as a possible cause. Supporting this is the fact that I did have the manifold off, and may have either missed or poorly connected/mounted some element of the job, or cracked the manifold, or something related to the air tightness of the assembly. Working against this possible is that it is intermittent... I mean if there were a crack, a hose off, something stuck in a gasket... it should be a consistent problem, and it is not.

3) Another component, connector, or wire: Yes it throws the MAP sensor codes, and not those of the several other sensors in the manifold assembly. But in my experience... probably those of others... it is not always as "cut and dry" as the code thrown, in that other problems might cause the system to think OK sensors and feedback is the culprit. But I doubt it.

So what I am going to do is try and test the wiring to the MAP sensor. I'll test the continuity from the connector to about 5 inches up. I'll test the voltage to the sensor from the computer, and whatever is listed in the manual, using the troubleshooting procedures listed. If the wiring all seems fine, then I will go over the entire assembly, and remove and clean each connector again. If the problem persists, I'll order a new set of manifold gaskets, and re-do the ENTIRE disassembly/reassembly procedure, carefully checking and double-checking every aspect of the manifold, throttle body, wiring, gaskets, and all connectors.

This is something I did wrong, and missed, or broke, I'm pretty sure. I just have to find it, and there's the rub. Trouble is I live in upstate NY, and don't have a garage, and it is the coldest part of the year. If it were still summer or fall, I would have had this apart and together already, and probably solved it. Hard to work under a car when it is in the 20's, and your tarp is laying on ice.

Thanks again for the input. I'll let you know how it goes.

EDITED TO ADD: First thing I will do is clear the codes, then unplug the MAP sensor and go for a drive. That way it will give me a good, general indication if the wiring and sensor are the problem, as the thrown codes imply. I can focus on those. However, if the disconnect causes new and different symptoms, then it is possibly something other than the MAP sensor issue at fault here.

 

No, my research indicates that when the MAP sensor is changed, you have to use a JLR SDD software or maybe a GAPII tool, also with a compatible comm device to remove/delete the old MAP married/registered to the main ECU of the SUV. If you don't do this the LR2's ECU still thinks it's communicating and using the old MAP sensor. It's not a reset and time issue but a delete and add issue. You will have to research it as it's now a software reconfigure issue not a relearn or time will update issue.
Basically, the LR2 or Freelander 2 needs to be told that the MAP is new and will need to be calibrated. Hey, I hope I am wrong but......

 

Thanks, Thor, but I looked everywhere and cannot find any such requirement for the I6 LR2, in the manual nor elsewhere. Perhaps you saw it for the later engines? The factory manual only tells you to swap in a new MAP sensor, nothing else in its 1400 plus pages. But I'd be very interested in seeing the source your research found, though, if you have it handy. Meanwhile, the problem is fixed and the engine runs fine with the new MAP sensor... see update in next post.