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2000 Jaguar XK8 (AJ27). Battery goes dead in storage while on battery tender (charger). Replace battery. Start vehicle, and it accelerates like crazy to excessively high RPMs. Tapped around and the issue went away. However, when I start the vehicle, it runs great for two seconds and goes into Restricted Performance. I pulled the codes as follows:
P1384 Variable Valve Timing Solenoid A Circuit
P0352 Ignition Coil B Primary/Secondary Circuit
P0354 Ignition Coil D Primary/Secondary Circuit
P1396 Variable Valve Timing Solenoid B Circuit
P0128 Coolant Termostat (Coolant Temp Below Thermostat Regulating Temperature)
I switched Coil B with Coil A - Same codes/same locations
Replaced spark plugs in cylinders 2 and 4 (L/S motor standing in front) - Same issue
Let vehicle run until Thermostat opened - Same P0128 code
Tensioners updated many years ago -
Erased codes/Performed hard reset - codes come right back before starting motor (Key on)
Power is going to both Variable Valve Timing Solenoids.
Suggestions on where to start with the coil codes?
Creedoe, to have that many engine codes that are not really related to each other, I would be looking at either the ECU or the wiring coming from the ECU into the engine bay. I have seen problems in the past where critters like the taste of the jaguar insulation and this causes them to eat the insulation off of the wiring, leading ot many faults. This is where some investigation under the hood and seeing if you can see any nice perches that a critter would be able to sit on and then look in that general area. hard to say what you may find. Granted, could have experienced a shock to the electrical system of the car and this fried the ECU.
Thank you Thermo. By chance, would you happen to know where the ECU inside the vehicle is located? I would like to check the connections to the ECU inside the car as well along with the condition of the ECU. If not, I can start my search with the available manuals on the site.
Creedoe, to have that many engine codes that are not really related to each other, I would be looking at either the ECU or the wiring coming from the ECU into the engine bay. I have seen problems in the past where critters like the taste of the jaguar insulation and this causes them to eat the insulation off of the wiring, leading ot many faults. This is where some investigation under the hood and seeing if you can see any nice perches that a critter would be able to sit on and then look in that general area. hard to say what you may find. Granted, could have experienced a shock to the electrical system of the car and this fried the ECU.
From the area of the ECU you're going to want to start chasing/following along the large wire looms to see if you can find anything unusual. Unscrew the air intake tubing at the top of the throttle body, unplug the mass airflow sensor just after the large air filter box on the RH side, disconnect the pinch clamp and remove the large-ish hose from the RH side cam cover that goes TO the tubing and put the whole air duct assembly aside. It will come off in one large piece.
From there, get a good LIGHT of some sort and start poking around. Especially behind the throttle body and around the space left by removing the air intake tubing. Follow both the wiring the best you can from say the timing advance solenoid from the RH side and see if you can follow where it leads.
There is also a LARGE plug behind and kinda under the throttle body, it's bolted to a bracket on top of the front of the transmission. Really look around in there for things that ain't right.
Much appreciate the feedback. I will have to wait until 1st thing Saturday morning for maximum light to examine.
Did the car sit for a long time?...Yes. But always started up every few weeks and ran like a charm. Vehicle would not pass smog because the Comprehensive Component monitor would not complete despite how many weeks I drove the vehicle following the driving cycle instructions to the letter. No Check Engine Light. No codes. Emissions clean. I have heard many possibilities such as, "You need to flash the ECU". However, I need probabilities, not posibilities. DMV representative refused to issue another moving permit because she accussed me of "taking advatage of the system". She has the brain power of an earthworm. So I was forced to park it until now. Used vehicles 30% higher than last year. So now is the time.
JayJagJay, I followed the harness from the ECU including wire looms from the coil packs and the surrounding areas, to all of the main looms going into what I would call a large box plug with additional harnesses. Then I cheked all throttle body connectors and looms. Grabbed all with a glove and wiring appears to be well intact.
JayJagJay, I followed the harness from the ECU including wire looms from the coil packs and the surrounding areas, to all of the main looms going into what I would call a large box plug with additional harnesses. Then I cheked all throttle body connectors and looms. Grabbed all with a glove and wiring appears to be well intact.
No Luck. Any Suggestions?
Hey Man. Good morning....
Man, this is a hard thing to tell ya, and I would hate to say this and send you down some rabbit hole. But this is where I would start checking - and yes, this is just a start... It seems like a lot at first but it's really not. Everything contained in these diagrams is really all found in an area about the size of a car
I'll supply a link where the OP was chasing a recurring p0354 code. He swapped coils around, did a lot of stuff, just to find in the end,,,, a SINGLE loose wire.
Also, you MUST find the electrical diagram for your car. I have a few snaps, but they don't tell the whole story. At first (at least it did for me a few years back) it's going to look like a plate of spaghetti, but after a while the diagrams really start to make sense. Anyways.
The screen shots below LOOK to show that the solenoids and the coils share a common CONNECTOR. It is the block that sits in a metal cradle on the top of the bell housing where the transmission and engine meet. It's just behind the throttle body. My guess would be, and this is just me, that there is something going on at that connector, wires coming into contact there OR maybe, one of the coolant lines dripped into the connector - or maybe a mechanic 13yrs ago spilled his hot chocolate into the thing - ya can't make it up.
Anyways, the wiring for these things is "connected" and run close to each other in the looms. Sharing common large block connectors, and such and it kinda HAS to be there, somewhere.
Here is the link and some of the screen shots
It's the PI & 2 - XX connectors in the description and diagrams that you'll want to pay attention to.
So. If you can and do download that ED electrical diagram your going to want to start looking at and getting comfortable with the info in section 4.1 4.2 Engine Management. My suggestion is before doing ANYTHING,,, just get used to looking at and deciphering the doggone thing. Til it starts to kinda click.
There are important ground points. Check these. Some you have to dig for by removing the little kick panel down where feet go in the cabin. Under dash bottom corner at the front of the door. ***EDIT*** I believe these grounds are in the LH and RH enclosures in the engine bay...
Once ya really be able to start to visualize which areas of the car are represented by these diagrams,,, then get the color scheme of the wire color scheme at hand or down, I promise you,,, it's really is not as monstrous as it seems.
Finer finer points here,,, more experienced members will be more helpful than I... But I'm open to helping where I can
First and foremost I don't know where to start in regards to thanking you for all of your efforts and input. Much Appreciated!
Second...Holy smokes! This is a lot. But I did happen to review the Engine Management scematic a couple of weeks ago so I am familiar. I take it that I should start with what the codes are related to (both VVT solenoids, Coil packs, etc..) and run them all the way back to the ECM and the block for the main looms - not to mention L/S and R/S Engine compartments along with everything that is detailed in the diagram. Whew! Ok, starting on Thursday thru the weekend until it gets done. Hope to have results for you shortly - and I will check out the link you provided as well.
I don't have good news. I have spent a lot of time under the hood and I am not having any luck locating the 3 grounds. I found what I believe are a heavy gauge and a thinner gauge set of black wires mounted to the outside of the R/F engine compartment. I can only assume it would be the EMS38/EM1BR/(EM2BR) on the diagram because it is 2 wires. But the color code says BK - I think that is supposed to be black and pink, but the two wires I found were all black - one with a serial number on it. I ran my hands through all of the wiring from the coil connector to the larger loom. All wires intact and all wires to the connectors on both coils pulling codes are intact as well. Unfortunately, your link in the email didn't work. Is there another way to forward a guide that would assist in locating where the grounds are? I am also confused about the description "Left hand Leg". Are they referring to the driver side kick panel? And should I consider pulling the kick panel on the passenger side to locate?
I don't have good news. I have spent a lot of time under the hood and I am not having any luck locating the 3 grounds. I found what I believe are a heavy gauge and a thinner gauge set of black wires mounted to the outside of the R/F engine compartment. I can only assume it would be the EMS38/EM1BR/(EM2BR) on the diagram because it is 2 wires. But the color code says BK - I think that is supposed to be black and pink, but the two wires I found were all black - one with a serial number on it. I ran my hands through all of the wiring from the coil connector to the larger loom. All wires intact and all wires to the connectors on both coils pulling codes are intact as well. Unfortunately, your link in the email didn't work. Is there another way to forward a guide that would assist in locating where the grounds are? I am also confused about the description "Left hand Leg". Are they referring to the driver side kick panel? And should I consider pulling the kick panel on the passenger side to locate?
Maaaaan,,, I read this the other day and should have replied. Apologies.
I'm hoping others can help in the location of grounding points, I will be looking again. I've been out and about and have had no way to be still and In front of the diagrams for the last couple of days.
In the ED, the one for your car (do you have a copy yet?), in the very first pages, gives a layout of ALL of the major ground points. You need a diagram of your own at this point.
Also my Man,,, as the member said in the very first reply (and I agree with him 100%),,, is that you are going to have to get your eyes on ALL the looms under the hood. Have you removed the cover for the ECU/M in the RH enclosure? It's a simple black plastic box... There should be four torx bolts around the rim of the black box. Don't worry, there is nothing to break under there. Have a telescoping magnet tool to retrieve and reset the torx bolts and an extension on the torx bit. The cover/case for the ECU/M is sealed, or it's supposed to be, and all it takes is a slow drip of water IF the seal failed to reek all kinds O havoc. Then, as the member said in the first response, if the car sat for any length of time the ECU M case makes for a wonderful mouse house. Ask me how I know
You'll get this. Don't get overwhelmed. It's just wiringAlso, use your judgement,,, being in the scene. Don't let me send you on wild goose chases...
Honestly, I don't know if the vvt, ignition and temp wires run thru the box under/behind the throttle body,,, hopefully someone else can say - if so, I would dig it out, separate the halves, and inspect and clean as well. There is a coolant supply thru the throttle body and the heater hoses run back there. If the PO had any kind of a coolant leak and water made it into the electrical block,,, well, you get the idea.
12-12-2021, 06:20 PM
Restricted Performance
