G'day all,
Been a few years since I posted as my S-types have been running beautifully until recently!

Hoping to get some help with my '01 v6 not starting - after replacing the relays 14 & 15 due to some recent non crank or non start episodes. It's now thrown the P1586 throttle malfunction code. Cranks and starts but then immediately stops with no throttle response. It's been my daily driver for over 2 years without any issues.

On my live data I can see pedal response on the potentiometers but no corresponding movement on the TPS potentiometers.

I've been reading about the 1586 code and it's described as communication issue between the TACM and the PCM. There are a few threads about people solving it through fuse resetting, changing relays, new battery etc. but seems there is no clear or definitive answer in most cases?
Does the SCP system have anything to do with blocking current to the TACM?

My other S-type has the exact same P1586 issue. It cranks and starts and then immediately stops as well. Happened after I was working on fuses and relays as well.

Anyone had any experience or luck in solving this one? I hope I haven't bricked my cars!

Thanks very much,
Cheers
Ben

 

I'd start with checking something very simple.
While I do not know the 2001 model, I assume that the same as on the 2004/2005 S-Type:
Check that connector UNDER the throttle body, just where the tube coming from the air-intake ends.
I think it's the connector to the throttle body control motor. This connector is located at a position, where it gets very hot, and every of those connectors in every S-Type will sooner or later disintegrate (as that plastic simply can not cope with those temperatures over time.)
So, you connector simply may have fallen off, or it's still hanging, but inside there is no longer electrical contact.

I fixed this on my S-Type by soldering a cable onto those 2 contacts and by adding a new inline-connector nearby.

However, there was a post here recently, where someone actually managed to find the exact connector (which disintegrated there) and replaced it. It was the correct connector, but it was from a totally different model (XF or something).

 

Had to do a double take. You’ve got two similar models with identical rare faults, both of which only happened after seemingly unrelated replacement of fuses and relays?

If so, I’d certainly suspect those new fuses and relays. The relays are more likely simply because they have moving parts.

Have you seen this?:

http://www.jaguarforum.com/showthread.php?t=69622

This was mentioned in another thread discussing P1586.

 

Hello Peter, thanks for the tip.
I've got the original type throttle body mounted in the front with different connectors - but there is something preventing current from powering up the throttle body when I turn the key to the on position.
Once I figure out why - I think the problem will be solved. 🙏

 

Hey there Karl,
Thanks for the link and yes the Relay 4 is where I think the source of my problem was.
I think the R4 was accidentally removed whilst the key was in the on position and I think that's what triggered the P1586 non start condition.
I installed a brand new 850cca battery, and essentially the engine failsafe mode didn't appear and the car proceeded to start right up!
I basically did the same thing with my other S-type that had the P1586 code and it has been 'cured' as well - using the brand new battery definitely made the difference!
It seems that by using a really strong power source the ECU and modules were fully powered up and the SCP communication error / throttle actuator fault went away - somehow?

Any way I'm stoked to say that the issue has now been sorted!

Cheers,
Ben