Ok a few months back I was getting P0101 errors from the MAF. I check the air inlet and smoked tested for leaks all looks good no leaks in the usual places (i.e. bellows air intake, also replaced the air filter even though that was only 5K miles old).

I then cleaned the MAF with CRC and problem still existed with lean errors and now restricted performance.

I then change the MAF and with the new MAF got P0101/P0102 (low voltage). So next I check all the wiring no problems there. So I assumed the problem was with the new MAF.

I replaced the new MAF, and with the next new MAF (3rd one) I now get P0172/P0175 bank 1/2 to rich. Also average fuel consumption with the two new MAF's has dropped from 14.3 mpg to 11 mpg!!

MAF is LNE1620BB (197408-0021 Denso) checked with Jag they say this is correct and part number has not changed.

Anyone any ideas ??? as I'm stuck thinking may be throttle body has an issue but who knows.

Thanks
Simon

 

When you change something as critical as a MAF, it is always recommended to do a hard reset so the ECM trims start from scratch and it doesn't have to catch up with the new equipment 'over time'.

 

Yes I did the hard reset after looking through all the posts on this issue and there are a lot!! I'm thinking its the elect connector. Reason different errors with two new MAF's (one high volts P0103, one low P0102).

I did check the wiring and re-routed the wire and re-tapped it at the joint above the alternator. This gives it a little more room. Note I had the drivers side (USA) engine mount go a year ago and didnt replace it for like 6mth so the engine would have been pulling down on the passenger side. Now the MAF cable has about an inch more play. I've also cleaned the plug and bent the female side pins to give better contact.

Note my plastic catch wedge on the female side is broken off not that this is a problem as the plugs fit together very tightly and does not seem to move.

Anyway lets see if this fixes the problem!

Thanks
Simon

 

Ahhh, now that makes good sense. I hope it fixes it too.

 

Well dont think that fixed it as my fuel consumption is still down at 11 MPG. I've driven the car for 58 miles and still no P1111 so ECM has not cycled yet guess it is seeing a problem.

I have a better ODB II reader now (scantool.net) so I should now be able to get the fuel trims e.t.c.

What info do I need to collect to help diagnose this problem and what rpms e.t.c?

Ok added the PID data at 650RPM idle and 2200RPM Think it all looks ok can anyone confirm? Pending error code is P0101 at the moment.

Thanks
Simon

 

P172/175 = rich run both banks..the mas air sensor will cause this but you seem to have been there done that, I had the same issue on my XJR for 10 months, some times would go for 4/500 miles and weeks then recode ..some times a couple of days... I wont bore you with the parts I changed with no fix...HOWEVER about six weeks ago I ran a vacuum test on the fuell pressure reg and the vacuum bled off ?? I replaced the reg .. so far so good has now gone over 600 miles with no codes...

 

1st you need to solve the P0101, have you already used an original MAF?

 

I had the same codes stored,some times one some times the other I was told by the tech that these are pending fault codes that the ECU had picked up and was still looking? even after the P0172 and P0175 had logged the ecm will continue to scan for any other hard code...again duing my test of the fuel pressure reg when one of the hoses to the reg was pulled a tiny bit of gas was seen dripping from It and would cause the rich run both banks not too many things will trigger both codes at the same time...The MAS being #1...

 

The original MAF puts the car right into performance restricted so I know that one has a problem. The other two I have, both new give different errors:

One gives P0101/P103
The other has given P101/P102 & last time I tried P0172/P0175.

Sometimes I can get to P1111 with no errors but then under hard acceleration I can get the engine check light to come on with codes.

I've checked the ohm reading between the 5 pins and for the two new ones they are the same but for the original one two pins the same and other two very different (from new ones) but I'm sure original one is dead.

I've checked the wiring and plug (tighten connection just in case) all seems ok. So i'm still thinking its MAF problem. I will spray some throttle body cleaner into all the areas where leaks could be just to check. But visually all looks ok ?I had the intake duct of and checked everywhere cleaned the breather pipes new air filter e.t.c Yes I do reset the ECM after I keep changing MAF's

The fact that different MAF's give different results suggests either MAF or wiring ? Wish I had a MAF that I know was good!! Does anyone have the Ohms values across the 5 pins ?

How does the car need to be driven to get it to cycle ? mine seems to take for ever to get to P1111 (like 60miles driving stop/start e.t.c)

Simon

 

The 1st MAF might indeed have an issue, as I know how sensitive MAFs are due to my experimenting, I personally wouldn't use the cheaper Chinese copies here. I take it that the 2 new ones you used where the Chinese copies, so best (cheapest) bet now is to try an original MAF The results from that test will be very valuable, especially as I would 1st suspect these units.

There are many (comprehensive) checks to get thru to get to the P1111, so pending driving styles it could be within 100 miles or even more. The MAF errors will also prevent certain checks to complete though.

 

Help with Trans fluid.....see my post in general tech help...thanks

 

OK got a MAF from a Jag dealer online ($202). This one looks the same as my original and came with the short intake sleeve. All installed so lets see if this cures the problem.

The Chinese ones ($44) look to be copies of the Denso. The shaft inlet was slightly lower and the components for the heat sensor are different. The resistance between pins 1-2 4-5 3-5 3-4 were the same though.

 

UPDATE
Well with the new Jaguar MAF does not look good. I've done about 30 miles of mixed driving and still on P1000 no codes yet but the MPG still at 11.7MPG when I used to get around 14.3 avg. So problem is still there just no codes thrown yet.

Short term fuel % trim - Bank 1 6.74% mean
Short term fuel % trim - Bank 2 5.14% mean
Short term fuel trim (Bank 1, Sensor 2) -1.56 mean
Short term fuel trim (Bank 2, Sensor 2) -0.78 mean
Long term fuel % trim - Bank 1 6.7% mean
Long term fuel % trim - Bank 2 4.85% mean
Closed-loop, using oxygen sensor feedback to determine fuel mix
Mass air flow rate 6.64 g/s
Intake manifold absolute pressure 46kPa
Intake air temperature 38C
Fuel rate 0.58 gal/hr

So guess we have to wait for this junk heap to throw the codes!! Mean while my smog test date is getting close and closer.

For smog test it says Evap System & Component System & Catalyst not ready. This is on OBDWiz

All 4 O2 sensors are all Pass for Low/High Voltage

MIL Off, # Trouble Codes 0, Misfire: Available = True, Complete = True
Fuel System: Available = True, Complete = True
Components: Available = True, Complete = False
Catalyst: Available = True, Complete = False
Heated Catalyst: Available = False, Complete = False
Evap System: Available = True, Complete = False
Secondary Air System: Available = False, Complete = False
AC Refrigerant: Available = False, Complete = False
Oxygen Sensor: Available = True, Complete = True
Oxygen Sensor Heater: Available = True, Complete = True
EGR System: Available = True, Complete = True

Now under OnBoard Diagnostics I do have one failed item
TId $0A Manufacturer Defined Component ID $11 (they all have this id) Value 65535, Min N/A, Max 33423, Units blank, Result Fail

NO IDEA WHAT THIS COMPONENT IS ??? Attached is a screen shot of this readout.

Thanks
Simon

 

This procedure has worked repeatedly for me to close the evap. test:

-Gas tank about half full.
-Drive around for 10-15 minutes and get the car well warmed up.
-Turn off engine for 5-10 minutes.
-Restart engine and idle for 13 minutes...do not touch the gas pedal during this period.
-Then as soon as you can, get on the highway and drive at a steady speed for over 6 minutes.

Not sure about CA, but most states will allow a smog pass with just one test not completed.

 

Have you done a full reset (so battery off) after you changed the MAF?

 

Yes I did the battery reset. Checked again for air leaks took the car for another 30 mile drive today and fuel consumption a little better but still have P1000 code and still have fail under Components TID $A0. So did some research and found this documents.

http://www.europeantransmissions.com...C-jag/obd2.pdf

ON-BOARD DIAGNOSTICS
V6 and V8 Engine Management see attached.

Covers
XK Range 4.2L V8 (normally aspirated and supercharged) from 2003 model year onwards
New XJ 4.2L V8 2003 model year onwards

NOTE MY CAR IS 2001 XKR SO NOT COVERED.

On page 5 I see this.

Conversion for TID $07: Multiply by 6.25/1024 to get result in kPa.
$09 $00 EGR system flow malfunction (GA changing rate low) g/sec
$0A $00 EGR system flow malfunction (GA changing rate high) g/sec

Now I know this document does not cover my car but is this the same or better still does anyone have this document for the 2001 XK series ?? and does anyone know what this error is i.e. do I need a new EGR value ???

Thanks
Simon

 

also look at the 02 voltage data, upstream only on both banks ... what is the voltage? It looks like you're getting some extra fuel in there, and TB opening up to compensate...assuming at idle this was taken? No RPM shown.

Remember, the 02 sensors only measure oxygen, not fuel, so if the sensor sees not enough oxygen, ECM throws more fuel into the combustion process.

 

Yes car was at idle O2 sensor all pass tests here the results. RPM 650 ish

See attached for O2 data tests say pass on all 4 they were all replaced 5K miles ago with no problem until MAF and P0172/P0175 code.

 

I didn't seen any upstream data - Sensor 1, only Sensor 2 which only is indicative of cat efficiency, not 02 measurement and ECM instruction. Got those?

 

See attached this is all the O2 sensor info on the PID mnitoring, also the Onboard monitoring TID $A1 thru $F1 all show pass

Thanks
Simon