A few days ago, I went to start my MY2009 XKR and just after starting, the DCS, ABS and engine Malfunction Indicator Lamp stayed on and got the dreaded 'ABS Fault' and 'DCS not available' messages on the console. I drove the car, hoping the fault would 'go away' but it stayed permanently on. Some time back I had a similar intermittent problem when I parked the car in Sicily, it rained and when started the same messages came up. At the time, I restarted the car and the messages went away.

Alas, this time, the fault persisted.

I keep a habit of asking the dealer to print out for me the stored DTC codes and browsing through them, I did notice a DTC code coming up relating to the rear right hand side sensor, so I now suspected that this sensor died. I had a go at cleaning the sensors (both rear ones) but still no luck. Noticed also that there was some corrosion on the suspect rear right hand side one.

I know that the workshop manual states that the sensors are 'active' sensors, but took a chance to measure their resistance; rear left hand side: infinite (as it should be); rear right hand side 30ohms, surely indicating that there was something wrong here. With the sensors removed, there was voltage (around 16V) coming to the sensors, so this confirmed that the ABS control unit 'seemed' ok. BTW, found a good document by ATE (the sensor manufacturers) about troubleshooting sensors, attached.

Ordered one sensor from the UK and installed it. Started the car; immediately, the DSC lamp went off; driving the car led to the ABS lamp to go off as well. DSC also worked round a corner .

My question is this: The engine MIL is still on. I do not have an OBD device (but intend to get a used VCM). Will this need to be reset or cleared or could there be another fault? Will disconnecting the battery clear the MIL? Apologies for the seemingly dumb question, but I'm still a newbie at fixing these things

Best regards!

Andrew

 

Andrew,

Although I always thought a scantool was needed to turn off the MIL, I was surprised to learn a few months ago that the MIL can be turned off with a 'hard reset' (disconnecting the battery cables and touching them together for around twenty seconds to dissipate the stored charge).

Provided the fault(s) which caused the MIL to be illuminated in the first place have been resolved, it will stay out.

A 'hard reset' does lose all the learned settings such as fuel trims which will then be at default values and gradually adapt. Radio stored presets will need to be set up again and, if you have a coded radio make sure you have the code available before disconnecting the battery.

Graham

 

Thanks Graham. Will have a go at the 'hard reset', though at this stage of my learning process I feel some trepidation

Cheers and thanks again!

Andrew

 

Andrew,

The XKR almost appears to have been built around the battery:







The cables and loops are more complex that the earlier models. Be careful not to short across the terminals.

Graham

 

Thanks again Graham! Some good bedtime reading

Mine's a convertible, so it's even trickier as I need to remove the luggage separator. It seems there's also a procedure for starting up after a battery disconnection/hard reset.

Incidentally, you're spot on re the fault code resets. See first para of attached excerpt from workshop manual.

Cheers!

Andrew

 

Attachment here!

 

That's the same procedure as the earlier 2003-2005 4.2 XK8/ XKR's.

Useful to know. I'll file that away in my knowledge base.

Thanks,
Graham

 

Most welcome, Graham!

Andrew

 

Started the car today and voila' : no MIL ! Wonderful; seems like the MIL resets after some time/number of starts with no fault.

Still on track for the Mongoose and SDD v 131.01, though.

 

How to remove luggage separator for access to wall in front of battery...?
Also is it possible leaving the drivers door ajar after sitting for a week cause battery to drain down to 4 amps...?

Best...

 

Welcome to the forums Claude,

The separator is secured onto studs on the firewall with four black plastic retainers which screw off anti-clockwise by hand:





It's then easier to lift out the separator if the floor section over the spare wheel well is lifted out first.

The battery could easily become discharged by leaving the door ajar for a week. Too many electrical functions don't go into "sleep" mode. It's almost essential to keep these vehicles on a battery tender (e.g. CTEK MX 5.0) if not using every day.

https://www.ctek.com/uk/products/car/mxs-5-0-uk

Battery age is also a factor in how quickly it will discharge. Five years is a general age for replacement although it can be as low as four. Some members report up to ten years but this is very much the exception.

With a partially discharged battery you are likely to get all kinds of weird fauly messages appear when you do get the car started. A full charge will usually resolve this.

Graham