Replaced MAP sensor, but still get P1108
 

Quick question,

I am getting a P1108 error which I assumed was my MAP sensor. I replaced it, but the light is still on on my dash and the code won't go away (even if I clear it, it comes back on after a few starts).

I am considering taking it into the shop tomorrow to have this looked at since I am assuming it is electrical. Do you all have any suggestions of things I can try first?

Thank you in advance!

Shawn

P1108 is an alternator malfunction. MAP sensor is P1107. Check the alternator circuits.

Try this web site for DTC code definitions

Jaguar Check Engine Light DTC Trouble Codes

p01108
 

MAP Sensor sensor ground circuit: open circuit
MAP Sensor to ECM sense circuit: short circuit to high voltage
MAP Sensor failure
I unplugged mine today to see what code it would trip. The engine died immediately and tripped that code so on yours the computer is seeing the computer so the wiring SHOULD be ok OR intermittently. While idling wiggle the wires if Ok take it off and clean it with carb cleaner.
MAP is Manifold Absolute Pressure
note that it's the MAP, not the MAF sensor. It's the small sensor with three wires on top of the inlet manifold, right at the back, near the bulkhead center:icon_banana: on 2.5/3.0 engines.

Are you confusing it with P01118 which is Manifold Absolute Temperature

Er... P01118 has too many digits...

Post #3 looks best so far :)

Thanks for this. I ran the engine and unplugged the sensor, but the engine kept on running -- in fact there wasn't even a change in the sound of the engine. This makes me concerned.

Thanks,

Shawn

Shawn, 3 things can cause the P1108 code (MAP sensor circuit high voltage). You replaced the obvious one being that the sensor is the issue. The second possibility is that you are not getting a good ground to the sensor. This can be checked by connecting a multimeter to Pin 4 (Black wire with a green stripe). When measuring to ground, you should be getting less than 5 ohms. If not (ie, more than 2K ohm), you need to look at the black/green wire to determine the issue with the wire.

Next, measuring VDC, turn the car to the RUN position (do not need to start the engine) and measure from Pin 2 (orange/violet wire) to ground. Are you getting more than 6 VDC? If yes, then you have a short between this wire and the battery. Hand over hand the wiring to determine where the problem lies. If no problem can be found, then you may have a bad ECM.

If you did not get more than 6 VDC on the above check, was the voltage less than 4 VDC? If yes, again, check this wire for a problem where it is being grounded to the body/engine. Repair as needed.

Next, you will have the car completely turned off, disconnect the plug at the ECM and do a continuity check between Pin 1 (Black/white wire) at the MAP sensor and Pin 127 (Black and white wire) at the ECM. Did you get less than 5 ohms? If no, you have an open in this wire and you need to make repairs. If you got less than 5 ohms, reconnect the plug at the ECM end and turn the car to the RUN position and measure Pin 1 (black/white wire) to ground while measuring VDC. Did you get more than 10 VDC? If yes, then the black/white wire is shorted to ground. Hand over hand the wiring to determine where the wire is shorted to the battery.

This is coming out of a Jaguar repair manual (cleaned up a little to make it a bit easier to follow). This should find your problem.

P01108
 

OOPS I added one to many 1s should be P01118

Code
 

I'LL stop now I did it again P0118

Thank you so much for this! I did the first two checks and got a .2 on the ground with the multimeter set at 200 Ohm. And 5.0 with the multimeter set at 20 DCV. I am now read to test the continuity. Is this the ECM and if so, how is the best way to get the cable off?


https://cimg3.ibsrv.net/gimg/www.jag...bf93240d63.jpg

Thank you AGAIN for your help!

Shawn

Just want to verify if this is the ECM and if so, what is the best method for removing the wires? I want to be sure I don't break anything if there is a certain way to remove the wires.

Thanks!

Shawn, you are going to need to find yourself a set of "5 point security bits" (see New 5 Point Torx Star Tamper Proof Security Bit Socket Set | eBay). This will allow you to remove the screw that you can see in the picture and then give you access to the pins in question. You might be able to find them locally if you have a large electronics store. It may be even possible that your local autoparts store will be able to special purchase something like this for you. But, you can also pick them up on e-bay for fairly cheap too.

looks like the issue might be the ECM. I can find a used one, however am I correct in believing that a used one can't be reprogrammed, but is basically for parts to repair the existing ECM? I saw in other threads that there is a compmay that does repairs if it seems to big of a repair for me to tackle.

You're not likely to be able to repair one unless you are used to repairing SMD-based PCBs.

I think your kind will be a Denso PCM so can be reprogrammed (or sent out for repair). They do not often fail and usually people have misdiagnosed a fault as being the PCM instead of the actual faulty item.

Shawn, the PCM is programmable. Unfortunately, this is a dealer level programming job. The only exception is if you have a very high end code reader (ie, you spent around $1000 for one), then you would have the ability to reprogram. But, if you have one of them, you would know that you had that capability.

Update
 

It's been a few weeks, but I finally got around to checking this. I was able to remove the ECM cover and plug unit and noticed that someone had previously spliced the black/white wire to a new black wire attached to pin 127. When I looked at the other side of the plug, I noticed that I couldn't see the metal connector that the pin on the ECM would fit into. Sure enough, the black new wire wasn't pushed in enough. I was able to push it in further with a pair of needle-nosed pliers so that I could see the connector inside the hole. I reattached the module and screwed it back in.

HOWEVER....

Now the car won't start. The inside lights flash, there are three clicks and the wipers (which are on auto) come on a few times. Could I have messed something up with the ECM or might this just be an issue with the battery (which is old, but recently recharged?) -- I did unplug it when working on the ECM plug.

Any suggestions?

Thanks,

Shawn

Looking Good!
 

Okay, so I hooked up the battery charger and sure enough the battery was low - it is a few years old so good time to get a new one.

Anyway, the car turned over and started chugging. I did a reading of the ODB2 codes and the MAP sensor was no longer showing, but I was now getting a P0205 and P0354 code. I looked up these codes in the manual (that thing is great!) and found the pin numbers for the ECM. Sure enough, looking at the plug, I couldn't see the connectors in the holes. I found the wires, pushed them in deeper so they were visible in the holes and hooked everything back up.

Car is no longer chugging and the engine light is off. I will monitor it for a bit to make sure everything is good, but it is looking very promising.

Now I've got to figure out how to read the ABS code -- grrrrr.

Thanks a lot you all for your help. I'll let you know if the light stays off.

Shawn

Is this the pinpoint test for 2008 XJR/Super V8 4.2 also? I have a P0108 after cleaning the intercooler and intake and MAP. Orange/Violet should be 5v reference? I am getting 1.14v at idle and it goes higher with acceleration to about 2.6v. I clear CEL and it does not come back on unless I restart.

Check workshop manual.

I was wondering if my computer sent a false code. My 2012 xj sat for 3 months and the battery died. When I jump started it. (from the battery in the trunk using body as a ground for the jag connected cable. when the car started up a gearbox fault code came up. I drove the car with no apparent symptoms. How do I insure the jag dealers does not stick me with an unnecessary gear job, 60k pampered miles