okay first of all thanks for checking out my post . i need help with codes 0174 and 0171 my engine light and restricted performance light is on and just recently my trac light and ASC light just came on need help please! this is every thing Ive tried already: replaced the seal around spark plugs , replaced spark plugs , check thoroughly for any vacuum leaks , new air filter , new aftermarket MAF sensor , fuel system cleaners , cleaned throttle body and air intake tube please if you have an idea anything i can try please . i have a 2000 jag xj8

 

P0171/0174 are usually vacuum leaks between the air filter and the throttle body but you seem to have covered most of that. The accordion pleats in the intake duct are famous for splits on the bottom just over the exhaust manifold and are hard to see unless you are specifically looking for them. Flex the duct so that even small splits will open up.

The other thing that I notice missing from the work you have done is the part load breather orifice and the tube to the throttle body. Clean the orifice with a 3/32nd drill bit held in a pair of vice grips. Check the tube for splits or disconnection from the back of the TB.

Beyond that it is probably time to get out the propane torch or the starter fluid can to check for leaks.

 

Just had these codes pop up yesterday so a very timely post. Thanks for info.
However can you explain the propane torch / starter fluid influence, other than torching the car in utter frustration!

 

I had a 0174 and it was the full load breather hose connection cracked so wasn't sealing / connecting properly. worth checking that if not done already!

 

An unlit propane torch and spray can of starter fluid are commonly used to check for vacuum leaks in the intake system. The vacuum leak point will suck the flammable vapors in and change the idle speed. A more modern and safer version is a smoke test using visible non flammable smoke to find the leak but few hobby mechanics have such in their tool box.

 

Air leaks are a real PITA. I changed every seal and o-ring and changed the intake manifold seals to no avail. I ended up changing the intake manifold itself and that finally did the trick. I guess it got warped on an overheat experience. Dang plastic. Removing the intake manifold is not the end of the world, but you do need a tool to get the fuel connectors off, and a few other connectors are a pain. The part load breather hose that goes under the intake manifold has caused problems for me and some other people too. Unfortunately, it goes under the intake manifold. I rigged up a smoke test to find the leak. Check on utube.
Oh yeah, some people have said that you can replace the part load breather hose without removing the IM, but that would be quite a trick.

 

I changed my part load breather as well without taking the anything else off. Came out one way but was impossible to get it back exactly the same way so we went over some pipes instead of under

 

Hi JimmyL, I sent you a Msg in private last month. Did you get that?

 

hey guys i fixed it finally !!!! 0174 and 0171 codes .check engine light is off now i had to tighten my fuel injector lines down and i ended up finding a pretty big slit in what i believe its called full load breather hose ( the black plastic hose with connector behind the throttle body ) i ended up just using throttle body cleaner and sprayed around the injectors while car was on untill i felt the car idle and it even turned off so then i was able to pin point the vacuum leak in both areas

 

Thanks for the feedback!

 

I too have been plagued with the 0171 and 0174 lean codes and just failed the emissions inflections due to the recurrent check engine light. I changed out the insanely placed fuel filter without effect. Thoroughly cleansed the MAF sensor still no joy. I carefully sprayed carb cleaner around the engine and air intakes without detecting any leaks. Before ordering a new MAF or o2 sensors I decided to resort to the cigar test. Well at least it's an excuse to smoke a decent cigar in the garage right? Found a pretty substantial crack on the underside of the dead end of the air intake -JB Weld epoxy and electrical tape for now and keeping my fingers crossed as I finish my cigar. A suggestion for these hard to find vacuum leaks

 

thanks, nice simple test and great excuse to have a nice cuban!

 

First and foremost, a huge thank you to those professionals who contribute to this forum who work on these cars in their daily job. I know myself how idfficult it is to sort theough the chaff of novice descriptions of problems that often lead you down a time consuming rabbit hole. Yes there are questions in this post ...

I've been digging through the JITS and various TSB's, after a battery disconnect - ECU reset.

Jaguar requires many different types of Drive Cycles and Reset ECU Adaption - but to find each Drive Cycle / ECU Adaption that might be required and in what specific order, you need to either know it exists by experience (may not be in the JITS but in a later published TSB / Recall) or find it by trial and error, or if you are fortunate enough to own a VCM IDS/PDS, the IDS/PDS sometimes walks the technician through the Drive Cycle / ECU Adaption step-by-step and references other things that must be completed FIRST.

I have Global Searched the JITS for my year/model/engine, but then I later find there are the TSB's I may have missed correcting the problem with a program update because the error does not reset or more often reoccurs due to the program update or Drive Cycle Adaption not being performed, that may cause running the Hamster wheel and never resolving the error code.

So it might be prudent to do some significant investigation BEFORE swapping a bunch of parts suggested by the Codes or even worse, by popular opinion ( " oh this fixed my problem then it came back after x amount of time ..." )

Q1. is there a list of Drive Cycles / ECU Adaption sequences by year/model/engine and most important, a list of ECU program versions fixing or addressing a related list of program errors by year/model/engine AND Sensor issues?
The key here is following the fault diagnosis tables and if after exhausting those diagnostic tests and verify the correct date code sensors (if they still are readable) and/or ECU versions which may not have been updated on your vehicle, THEN you replace the sensors or update the ECU, unless the ECU is part of a Recall or TSB applying to all vehicles in a range. Is there such a set of lists and where?

Q2. are there Drive Cycles and/or ECU Adaption sequences that must be performed / initiated only with the IDS/PDS computers - that is, it is a waste of time to try to reset a condition unless you start with a IDS/PDS connected and are able to perform the test as stated in the Procedure?

This second question I ask because a lot of people seem to be running the hamster wheel on some codes, when in the JITS it specifically says to hook up the IDS/PDS computer and only reset certain codes or conditions after specific repairs are completed and then perform only a specific drive cycle process - OR there is a TSB/Recall to Update the ECU that must be performed first? I find at least 3-4 different codes that result in cold start / short start/stop and driveability issues that were patched or corrected by ECU updates.

Q3. What specific sequences of Drive Cycles MUST BE PERFORMED to be met after a reset of the ECU to restore full drive-ability - assuming all repairs have been properly satisfied, and what versions of the ECU must be in place first?

Having worked in several automotive factories and Factory Emission/Environmental testing facilities as a control systems professional , some of these drive cycles are performed on a rolling road using very specific test procedures and then continued on the 1-2 laps following specific driving parameters on the test track to get the vehicle in a Driveability state that may not be achievable with any"normal" vehicle driving after a repair.
Other problems are conditions that occurred after the vehicle leaves the factory, resulted in finding a program error that requires an ECU update or it will NEVER be resolved following OLD repair procedures.

An example of this is in the JITS Service 303-14 : When to Carry out adaptations as below and in what sequences attached below ....

And remember there are subsequent TSB's ( not included in this post ) that also state the problems can ONLY be resolved with a flash of the ECU with an update - indicating a program fix for an error, hence you might be running the Hamster wheel cycle if your ECU is not up to a certain level fixing actual programming errors.
This is getting difficult for our older cars as most dealers want nothing to do with a 20 - 15 year old car.

Here are a few things I found - which tests MAY or MAY NOT have been updated in a subsequent TSB/Recall:

..

From JITS 303-14 ECU Adaptation Procedures




From JITS 303-14 Fuel Adaptation Drive Cycle - these above table values are most likely In-Plant test parameters performed on a rolling road right after final assembly, for example "Site" or "Step" 4 requires a significant throttle opening under load for 2 minutes that might achieve 100 MPH or better in top gear, or significant RPM range held in a lower gear but not necessarily achievable in the specific order of 1,2,3,4 and timed specifications on a regular road without some test interruption.




From JITS 303-14 Diagnostic Monitor Completion - there are a host of Drive Cycles tests for EACH section and EACH must be carried out within specific time frames or Default values are loaded - potentially causing later errors.




A lot of these are very specific conditions fulfilled on a rolling road in the manufacturing plant right after Final Assembly connected up to the Factory IDS/PDS, then completed on the driving track for 1-2 laps following a specific set of instructions the Driver Technician follows also connected to a portable IDS/PDS, and some may not ever be achieved in normal road driving over a period of months.

So for we DIY folks, can we come up with a set of ECU Adaptions / Torque Pro parameters that can reasonably be done by the DIY'er or, state when it is a waste of time because specialized equipment or an ECU update is actually required to be successful?

This is why we need to develop some specific custom access using a tool like Torque Pro to access specific parameters, including ECU revision level, Vehicle VIN and such.

Remember, a lot of these test procedures were developed when the car was first manufactured and only updated when there was a significant dealer feedback issue typically within the warranty period - then totally forgotten about due to a new model year.

We are a small owners group with a very low number of total production vehicles that are still on the road with a wide range of configurations.

For me, I think both my 2000 XJ8 and 2001 XJ8 each exhibit issues that I later verified are documented in TSB's where I now need to locate a way to update the ECU to the version that resolves the problem - Cold Hard start after short start in cold weather and other "false codes" , etc. that might need very specific Drive Cycle steps, for one example. And since the local Dealers had zero followup or the owners did not respond, neither have the stickers for the required updates and are not reflected in the Service Record.
Fortunately the local Previous JLR dealer who did not care for any customers Jaguar if it was out of the immediate short warranty period or greater than 2 years old is loosing their franchise and the new Dealership on the block are happy to accommodate old TSB issues when they are officially open for business the end of August 2018 - unfortunately at 2018 JLR Dealer service rates which very easily justifies finding my own VCM IDS/PDS setup.

This is a lot of content and expect a lot of the answers to these solutions are disbursed throughout the full range of this Forum or hidden in linked information or hinted to in another models Forum that shares the same configuration and year. Jjust collecting them into a logical sequence without the chaff is the challenge!

I hope this flowing stream of (un) consciousness helps some, and points others to review their try-this-part swap / Easter egging style repair process and promotes a bit more troubleshooting diagnostics.
.
Cheers!

 

I'm not sure why you resurrected this old thread instead of starting a new one. That said, I have disconnected and reconnected the battery of numerous X300, X100 and X308 jags, and never found it necessary to go through any of the ECU adaptations to which you refer.

The cars would start with a high idle which would settle back quickly, perhaps shift a little rough at first, and display the P1000 code for several drive cycles. But they would all run normally and the P1111 would show up unless there were actual problems in the emission control system.

There have been owners who had to go through the drive cycles you noted to have the ECU complete the readiness requirement, but that is not a common experience as far as I have been able to deduce.

 

I guess my questions about following the Jaguar procedures for ECU "Adaptions" were waste of your time then, very so sorry in inconvenience you.

 

Sorry if I was not helpful. It was not my intent to be insulting. Perhaps a member with greater understanding can provide the information you are seeking.

 

All I can comment on in response to the specified procedures, is I have yet to find a car that can't, at some point during normal driving, achieve all the parameters which will ultimately sort itself out. However, I drive 40 minutes each way for work, with a mix of country and in-town driving. If it's someone that rarely drives their car, and only does for 5-10 minutes at a time, then yes, those conditions might never be present enough to complete the cycling of particular monitors.

The problem is that they outline these steps and when you read them, you think wow, that's complicated and very specific, how will I ever be sure to hit that mark exactly. But in truth, my guess is 95% of our cars will complete them if you just take it out for a 30min drive in mixed traffic conditions for 3-4 days in a row. I had a major vacuum leak throwing codes left and right. Fixed it, cleared the codes on Torque. The second night afterwards, on the way home, the monitors on Torque all cleared green and a P1111 showed, and the next morning I went down and had the car inspected. Never had to drive it differently, or even pay attention to coasting to stops, or between speeds, or anything of the sort. If in three days of driving, and knowing for a fact that anything keeping a monitor from clearing is fixed, then maybe go back and look, but that's going to be very rare. More likely that if a monitor isn't resetting, there's still a hiccup somewhere.

 

Let's begin with a series of questions:

• What is actually wrong with your vehicle(s) that requires such extraordinary completion of the drive cycles?
• Is the MIL illuminated, and if so, which DTCs are stored?
• What is the age and condition of the battery?
• What is the battery voltage across the terminals with the ignition in the OFF position for a minimum of ten minutes?
• Has any work recently been done to the engine(s) and if so, what type of work?
• What is the fuel pressure at the schraeder valve in the engine compartment at idle and at WOT?