Alright guys, I've had my Jag for quite a while and have taken care of it as best I can. While driving today on the interstate, I came across the "Failsafe Engine Mode". No engine light yet, pulled up the code P1584.

Throttle Control Detected ETB Malfunction

Freeze Frame Data

Fuel Sys 1 CL
Fuel Sys 2 CL-Fault
Calc Load(%) 29.02
ECT (*F) 208
STFT B1 (%) -3.13

The Car is a 2000 S-type 4.0L engine.

Id love any recommendations before I take it to the dealership. Thanks to anyone who takes the time to look this over, I appreciate it.

 

I can't find anyone who's had that before on here.... commiserations!

On your era car there is a separate TACM (throttle actuator control module), i.e. an electronic unit told what to do by the main engine controller (the PCM). P1584 means the PCM has decided something's wrong: could be wiring, the motor driven by the TACM or the TACM itself. Or a confused PCM (it happens, though don't go assuming it).

Well worth checking for signs of damp/oil around the relevant parts (you'll need JTIS or the like but it's such good value off ebay or download if you've the patience). Also, check the wiring and connectors.

Or your dealer. Might be expensive if they just assume it's bad and swap it!! (But if they swap the whole throttle with TACM and motor then VERY expensive).

 

Thanks for the reply jagv8,

I know what part your talking about. I took the whole throttle body off yesterday to take a look at it. Everything seemed fine. Cleaned it up a bit. One thing I did notice, is a noisy annoying hiss/whine coming from somewhere around the throttle body. My guess is that something's about to fail.

My next question would be, is this replaceable at home, or do I need the dealership to program the TACM with the PCM?

 

Find that hiss!! It may well be the problem. It sounds like an air/vacuum leak. It needs fixing urgently and may also be what's annoying the TACM (which won't hiss as it's just electronics).

I don't think you can replace this stuff because I think it needs coding into the PCM, but a tech may help about that.

 

Alright jagv8,

I'm getting a new code. One of the cats is dying.

P0430
Catalyst System Efficiency Below Threshold (Bank 2)

Could this be affecting the TACM? Or is this another issue altogether?

 

The hissing is probably causing it. An air leak ruins fuelling and your cats are at risk. You want to fix that leak or get it fixed fast. Until then don't drive the car unless you have to.

 

Had a garage replace both catalytic converters for a good price. Car runs great now, but I'm still getting the code P1584. The garage I went to is saying the Idle Control Valve is messed up. This is not a Jag dealership therefore, I'm somewhat hesitant. Could this be the problem?

I'm not really getting any Idling issues. The car is as smooth as one can hope for. The only thing I've noticed is that when the car is either in park or neutral, it idles around 0.9 RPM's and I get a strange noise. And when I put the car in D or R the Car idles at 0.4 RPM's, and noise disappears. Is this normal?

 

The car doesn't have such a valve. Er.... was anything genuinely wrong with either convertor?

S-Types use a sealed throttle body for everything including idle control. Don't let them mess with it as they are mega-costly.

900rpm sounds a lot but you have an older car than my 2004 STR, which idles at about 650 rpm. Maybe someone with a 4.0 can say what theirs does.

I thought you had a hiss - what was that or is it still there?

 

One of the cats was completely clogged, checked it out myself. The other was done simply because I asked him to do it, and I got a good deal. Didn't want to go back in 6 months. Code for faulty cat disappeared right away.

This is the part they're talking about. It simply connects to the throttle body. I'm still getting that weird hiss.

http://www.partsgeek.com/gbproducts/...ek+Google+Base

I appreciate you patience and replies jagv8. Thank You

 

Mine idles around 600+ and if you hear a hissing and your idle has increased, your car is taking in more air than it should, something like they said or intake device is leaking in too much air. Have it looked at by a " Jaguar" person. You may decide that you can do it, or take it somewhere else for repair. Does it have high miles? I read somewhere on this forum that someone used duct-tape to stop a leak of an intake device LOL , Hey ,the intake devices have plastic parts and duct-tape can take some heat.

 

It's news to me if there really is an idle air control valve. The workshop manuals don't show it as far as I can see on the electrical diagrams and it's not on the other sizes of engines - apparently. The manuals do refer to it physically so it's very confusing. I've no access to a 4.0 so can't do more. It shouldn't hiss, though. If you have a hiss then you have a leak. Leaks need fixing. If you do have a leak that can easily account for your damaged cat(s), though so would misfires e.g. due to failed/failing coil.

I wouldn't use duct tape as it's not going to last and also unlikely to be air (vacuum) tight.

 

Yes listen to JagV8.... Hissing bad...Your cats probably failed from the problem. My guess is it has been a problem for a while and is getting worse...Check the throttle body and make sure all the connections are tight. Then follow all the tubing and check for cracks and leaks. Tighten things up as you go..Won't hurt..And please, it's not a Yugo, NO DUCT TAPE......

 

He , You know I was kidding, "RIGHT",about duct tape. Only" Nascar " pit crews can build a car with that stuff.

 

Little update on my current situation.

Took the car to the dealership yesterday. Mechanic had it for well over 2 hours. Seemed clueless as to what the actual problem was. I saw 2 Jaguar mechanics scratching their heads over the issue. Not a pretty sight. They drove the car multiple times, moved it from one door bay to the next, and reset the code multiple times. They fixed my hiss, but the code p1584 still comes up with "Failsafe Engine Mode".

There diagnosis of the issue; the cat needs a complete throttle body and/or new oxygen sensor on bank1. Personally, I think they're full of crap and they have no idea what the heck the car needs. That was there best guestimate.

Needless to say, I wasn't exactly pleased. And managed to get out of paying the $120 diagnostic.

My question to you guys now is, can I buy a used throttle body and install it myself? Does a used throttle body from another 2000 V8 S-type need to be flashed? And, would an oxygen sensor be giving me all these headaches?

Oxygen sensor on Bank 2 was replaced 2 days ago.

Thanks guys, appreciate it.

 

There are places that remanufacture parts, including the TB. Usually you'd send yours away and get it back fixed, I think - but google to find them then call them and see.

Bear in mind that the code is a CIRCUIT malfunction, so it's something ELECTRICAL/ELECTRONIC either outside or inside the TB. Could be the TB but could be the PCM or a harness or connector. But of course could be mechanical causing a circuit malfunction (actually, that includes a connector when you think about it).

Ideally you'd find a jag specialist actually worthy of the name. Is it too far to the next nearest one?

You have to bear in mind though that you have a rare code on a 10yr old car which is itself quite rare.

As it could be a wiring fault, the wiring diagrams are on JTIS so you could check the circuits out or get an auto elec guy to do it.

 

I too, had the same code yesterday. At a stop light, engine stalled with FAILSAFE displayed. I turned the key to off and then started her up. Failsafe was gone but MIL was illuminated.

Used my scanner (AutoEnginuity) and read the codes.
P0133 O2 Sensor Circuit Slow Response (Bank 1 Sensor 1)
P0153 O2 Sensor Circuit Slow Response (Bank 2 Sensor 1)
P1584 Throttle Control Unit Input Circuit Malfunction


After clearing them all seems to be OK. Strange thing is, I replaced all O2 sensors about 6 months ago. This caused me to run an O2 test and I found that B1S2 O2 and B2S2 O2 Fuel trims constantly run at 99.06% each. Sorry to say I have no idea what that means.

Sorry if this is a hijack of the thread too.

Mark

 

If you want help, how about starting a new thread and in it put:

version of AE you have

status of the monitors

At idle:
whether running CL (closed loop) on both banks (or status if not)
fuel trims (short & long, both banks)
all O2 readings
other sensor readings - but if you've got Enhanced AE just the emissions-related ones will do

any DTCs and their freeze frame data

Attach screen shots if easier - you can image just the AE window using Alt+PrtSc

Omit anything that seems like too much work (but it may mean there's not enough to go on).

If you graph the O2 sensor voltages, do B1S1 & B2S1 look similar and swing between about 0.2V and 0.8V? Do the ones for B1S2 & B2S2 swing far less often, if at all, and stay between those voltages?