I can read the codes and see many posts regarding code 1642. What I can not seem to find is a list of the most common sources of this code. I also do not know what "CAN circuit" refers to.

 

Hi Larry,

CAN stands for Controller Area Network, which is the serial bus by which the various Electronic Control Units (ECUs) in the car communicate with one another, including the Engine Control Module, Transmission Control Module, Anti-lock Brake Module, Air Suspension Module, etc.

Regarding the 1642 code you read, what was the letter preceding the code? I assume it must have been P since you associated it with the CAN short circuit. The Powertrain section of the Workshop Manual (available in the HOW TO section of this forum) shows two different issues related to a P1642 code:

Accompanied by an Amber warning light, P1642 indicates Restricted Performance, Engine speed limited, Reverse throttle progression enabled.

P1642 can also represent a CAN circuit malfunction: CAN short circuit fault, Control module failure - check for additional logged DTCs to locate control module source. For CAN tests, we are referred to the Communications Network section of the Workshop Manual.

Without another code to indicate which ECU circuit is effected, I'm not sure where you should look first, but a short circuit could indicate a problem with a wiring harness somewhere. I assume you would have noticed if your code were due to the scenario where Restricted Performance is imposed.

Sorry I can't help more - hopefully someone else will chime in.

Cheers,

Don

 

Don,

Thanks for the reply. Actually the code was accompanied by a Yellow "Failsafe Engine Performance Mode". I only retrieved the code after. No check engine light ever illuminated. Only other code retrieved was P1111, which i read can mean the end of the scan and no other codes exist, but the explanations I have read are somewhat confusing. I will check the instructions on the forum, but I was hoping for someone to chime in with a "common" source of this code, or a progression to follow. By the way I may not have posted my car is a '99 Vanden Plas, 95K miles. No other symptoms or unusual occurrences prior to the yellow light and "failsafe" mode.

 

Hi Larry,

Your '99 VDP is an X308, so it would be worth re-posting your original question, plus the information about the yellow "Failsafe Engine Performance Mode," at the X308 forum. This is the X350 forum for XJs from 2004-2009, and the information I gave you was from the X350 Workshop Manual. It may or may not be correct for your X308.

You can add your vehicle's model, year and mileage to your signature in your user Control Panel, which will help others give you more accurate advice (see my signature below).

You can download the X308 Workshop Manual and Electrical Guide from the HOW TO thread at the X308 forum.

I'll see you over in the X308 forum and hopefully someone will have some specific recommendations for you.

Cheers,

Don

 

Don,

I am sorry for placing the post in the wrong forum. I will get that corrected and I certainly appreciate your help.

Larry

 

Larry,

No apologies necessary - we just want your post to generate replies from folks who are more knowledgeable about the X308. I have only a general familiarity with your car, but on the X308 forum you'll find many owner-mechanics who know a lot from personal experience and will be more likely to be able to help. Hope you're able to track down the source of your issues soon.

Cheers,

Don

 

The P1111 code should always be present. It means the car is ready for an emissions check and all 5 readiness monitors are complete.

If you clear the codes you will see P1000 and that will eventually turn to P1111 as you drive and complete the readiness monitors.
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trying to get my jag ready for emissions . lean bank 1 .plugged in scanner .got all kinds of lights on .it is 1642 .my ? is will it reset itself after a few cycles or do I have to manually rest it and start all over------I have to drive 200 miles + - to get my im readiness ------thanks

 

Hi Mark,

Your message is a bit difficult to decipher. If you could, please give us more details, such as the year, model and engine of your Jaguar.

Diagnostic trouble code P1642 indicates a short circuit in the Controller Area Network (CAN) or a problem with a control module. If it is an intermittent fault, it is possible that the code may go away on its own but reappear in the future.

You also mention a code indicating "Lean, Bank 1." What was the actual code, including the prefix letter (P, B, C or U)? If other codes were present, please share them with us. If any symptoms of malfunction are present, please describe them so we have the full picture.

Also, if you can please use capitalization and edit your next message for clarity before hitting "Submit," it will help us better understand your concerns.

Cheers,

Don

 

I had a bank 1 lean code last week. have been driving car for about a week trying to get the readiness of the emission system to reset. plugging in my scanner at times to see where I stand. while driving to work this morning I plugged it in(or tried to) that is when I got the 1642 code along with transmission fault, stability fault , emergency brake fault, along with my temp gauge and tachometer are not working . thanks

 

sorry it's a 2005 xj8 normally aspirated h 166000 miles

 

All codes have a letter and it's vital to use it. Then use Search.

Clearing a fault will just make your life harder when a fix is what's needed.

 

Hi Mark,

When multiple seemingly unrelated codes appear, the first thing I suspect is low battery voltage while starting the engine, either due to a failing battery or charging system, or to corrosion on battery power connections and ground points between the battery and the major ECUs (Engine Control Module (ECM), Transmission Control Module (TCM)) etc. You've had colder temperatures than usual in Georgia, so that may be a factor.

Corrosion on ground points is another possible cause of CAN-related fault codes. Note that on an X350 the ground points are made of all aluminum parts, including the threaded stud that is welded to the body or frame, the wire eyelet/ring terminals, and the 13mm nuts. A microscopically-thin layer of aluminum oxide forms on these parts and resists current flow, causing problems in sensitive electrical and electronic circuits. Some of the grounds are easier to access than others, but their locations, along with the battery power connections, are all shown in the Electrical Guide, which you can download here:

Jaguar X350 Electrical Guide 2005

Note that the torque spec for the ground point nuts is a very low 6.5 ft. lbs., or just over hand tight. Many members have learned the hard way how easy it is to snap a threaded stud off of the body by overtightening the nut.

To clean a ground point use a small brass-bristle wire brush and zero-residue electronic contact cleaner. Do not use sandpaper of any kind, which will leave scratches in the aluminum that will only promote more rapid corrosion in the future.

To understand what Diagnostic Trouble Codes mean, it's important to refer to the official Jaguar documentation because their definitions and possible causes often differ significantly from the generic definitions you find in google searches. You can download the DTC Summaries guide here:

Jaguar X350 DTC Summaries

One thing to be aware of with an X350 is that the alternator charging voltage range is higher than in most cars, so the battery has to be capable of handling these higher voltages. The original Varta batteries used silver calcium technology, but are not readily available in the U.S. Our member Box has confirmed that the Exide Global Extreme batteries sold at Home Depot use calcium technology and are well-suited for use in an X350. I have installed several of them in Jaguars with excellent results, and the good news is that they are very affordable. If you replaced the battery in your car with a standard lead-acid or AGM battery, it may be aging prematurely due to the high charging voltages.

Cheers,

Don

 

I have recently resolved P1642 (and P1638) by cleaning the connectors in the ECM to Instrument cluster harness after visually niinspecting them. No more CEL and no more "restricted performance" messages.

 

This has been awhile but what if the CAN fault code comes with these other codes associated with teh P1624? I wish there is a "translation" for these fault codes to plain english....otherwise the dealership solution is to just swap out the entire transmission and ECU... when the transmission works perfectly fine and the gear skipping only happens once in like two months when garage valet parking drives it (suspect reverse gear back into first).

TC: P074A00, P284500, P284600, P285800, P060A00, P17F700, P14F900 -- P1624.

 

Your dealership probably has no expert in your car model so is in effect guessing. Probably best to ignore them.

 

NEVER do ANY transmission work before making 100% sure the fluid level is correct. What does the fluid look like?
You have a ton of codes not normally seen? Has the car went thru anything? Repairs?

Is the dealer a Jaguar dealer? Have they cleared codes and then checked what came came back?
With the gear skipping it does sound like a transmission problem? Why do you say the transmission is fine if it's skipping gears?
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