Hi Folks,

I am having an issue that I could really use some advice about.

About five weeks back got a CEL message and hooking up an OBD2 reader got the code P0101 - MAF sensor.
Pulled both out, they were very dirty, replaced air filters and and cleaned the MAFs with MAF cleaner, cleaned all the connectors with DeOxit and lubed them with electrical grease, reassembled and cleared the codes.

All is wonderful! - almost.

a few days ago I went to get the car smogged and the test could not be run because the Oxygen monitor was not ready. No pending codes were present. I was told to drive around for a few days, and drive I did! I have driven about 120 miles, tried all sorts of Jaguar drive cycle methods, (including 10 mins at 55 mph, coasting to stop driving at 3500 rpm and coasting resting at stop etc etc) and I cannot get my monitor to be ready for the test.

Just to add to the complication, and I don't know if this is becase of the various driving exercises, (during which I used all types of gear shifting - paddles and S mode) but now I have got a U0402 - "Invalid Data from TCM"

I must stress that the car drives perfectly! Everything works correctly, transmission modes, paddles, downshifts - all is exactly as should be.

I need to get this Oxugen monitor to complete its drive cycle!

Please help!

Thank you

Phil

 

I was told same thing I drove the car for several hundred miles and it cleared and all systems monitored on my 08 XK

 

Generic reader is probably only catching the first 5 digits. The 6th and 7th are more specific. I think you need those. You could be looking at a few things from linkage to fluids. Here are some basic checks:

Without the specific code I would start right to left on the chart above.

 

Thank you both... I will look up some of the things suggested, but as the U0402 is not a hard code I will not suspect anything, unless it does convert to a hard code. I am starting to think that I may have to drive a few hundred miles to re-set the O2 monitor - I have patience, but I am not so sure about the glorious CA DMV!

If anyone has any suggestions on how to expedite this process he would be worthy of a serious bout of toasting!

Phil

 

Clearing the codes is what cleared the monitor. (In future if you fix a cause of a code you can just leave the code there and it will self-clear (after 3 warm ups) without clearing any monitors.)

So... now, about hunting for the cause of it not setting again... May be painful, sadly. I'd start by looking closely at OBD live data for sensors etc hoping for clues.

 

Thank you JagV8

I have learned my lesson in clearing codes! I did have question as to how the codes eventually clear themselves when there is no longer a sensor report out of limits so thank you for explaining that.
I spoke to a helpful service manager at Galpin Jaguar (thank you Leslie) who told me that the best way to expedite the readiness of the monitors was to drive at 45-55 mph with little throttle deviation and to pull over each 10 minutes and allow to idle for 15 seconds at a time. I may need to do this quite a few times. They have no method even at the dealer to expedite this, as it is something controlled by the EPA.

Thanks to all of you helpful people here on the forum.

Phil

 

Epilogue,

So after several days driving, at various speeds and durations, glanced down and the code reader finally indicated that the O2 monitors were now ready - with a delightful green light to boot!
I took the car into the Smog shop and it passed with no issues.

The U0402 soft code went away on its own (apparently this is a manufacturer specific code (and could have been triggered by something as simple as a bad TCM communication on start)

The O2 monitors re-set at 189 miles, just for the record.

What may have helped was steady driving at 45-55 mph, no large throttle moves, maintaining 1/4-3/4 tank of gas, allowing to idle 15 seconds each time I stopped and no use of any driving mode other than "D"

I hope that this helps someone!

Thanks to all who helped me,

Phil

 

Awesome!

 

Thanks for closing it out.

 

Hooray!

 

Lucky you. For future reference, mine took 260 miles to become ready.

 

Something is probably marginal i.e. just about in / out of spec. You could try OBD live data in case you can get clues but do NOT clear codes or you clear all the monitors.

 

Good idea. The only place to drive at those recommended slow speeds for extended periods, with periodic pullovers to coast and idle, is on the interstate/tollway highways in urban areas, where you become a road hazard to the regular 85mph pace.
Thinking that if I’m ever in that situation again, where I need the monitors ready, in order to pass an emissions test to renew my plates, I’ll put the car on a lift and run the sequences.

 

My O2 stuff reads pretty quickly, it's the EVAP on mine that takes a year. Same with most cars I've had.

 

Interesting, my EVAP cleared the first day of doing drive cycles.

 

If it's a marginal (or wrong) sensor you can look parked at idle.

Do that anyway (warmed up engine) to check idle fuel trims.