No Crank, this one will stump you

[MarkinMaine]

It’s been a long time since I’ve had to post one of my own issues.

It all started with a bad P/S line, no big deal. Then it went very bad.

This has what’s been done.

Pulled air box, and intake pipe to plenum, to clean up P/S fluid. Cleaned it all up, reinstalled all intake parts. Started it up, drove off ramps, pulled back into driveway and noticed the Christmas tree including coolant temp light. Shut her down immediately, that was the last time she cranked over.

Now I get the Christmas tree, and all the fault associated with the classic “low battery” issue. including "cannot set park brake"

No crank, and can not release gear shift from park. I also noticed that the steering lock doesn’t lock. All the rest of electrical works fine, ie lights, seats ect.

I have checked the following:

Battery was good but 7 yrs old, changed to new.

Every fuse on front, and rear box.

All grounds are clean

Maf connection and all connectors that were removed for intake/filter box cleaning

“Not in park” sounds when pulling lever towards driver

Bolts on transmission cable present and tight

I can scan codes, but where to start? Live data?



It seems to act like its in gear. No crank. No locking column, no interlock unlock function on shifter.

The shifter does light does light up in park.

I have not checked mega fuse in boot, passenger fuse box

Everything I’ve read covers some of the issues in each post, but nothing definitive.

I am too far down the rabbit hole at this point.

Some have had issues with the front fuse box (relays), and others the shifter unit. Don’t want to throw parts at it just to guess. $$$

Thought it might be the interlock brake switch but that shouldn’t keep it from cranking

I’ve been staring at the diagrams for days, and can’t pinpoint which is the common denominator.

While watching the live battery data, the voltage doesn’t drop at all when trying to crank

Infotainment screen blacks out while trying to crank as it should

I have not done a load test on the new battery, but same thing happens when hooked up to jump start. Even a poor new battery should lock the steering and unlock the shifter


I know that's a lot but really need some help on where to start checking pinout, relays ect.

Thanks

Mark

2006 SV8

______________
Mark
Present
2006 Super V8 (X356)
2009 L322 Range Rover HSE
2001 Range Rover 4.6 HSE (passed down to my son, I still fix it)
1972 Land Rover 88 Ser III
2014 His and Hers VESPA LX150's
2020 Vespa Primavera (hers, she added another one)
Past
1990 Range Rover County
2001 XJ8
1970 Land Rover 88 IIA My first British love.
1990 XJ-40 VDP "gone but never forgotten" Still smell the leather

[J4CKO]

Have you got a code reader ?

JUst scan it and then stick what comes back on here,/Google, maybe clear them and try it.

[guards red]

Live data from the transmission will tell you if the gearbox thinks it is in park. If it's not, I would start there..

[skhannes]

Lots of guessing w/o any codes.

I will throw in with a wild card to consider and check.

If memory serves, these circa Jaguars had a safety kill switch and it could/should be tripped to disconnect the battery in an accident event. It also could possibly be tripped in a miswired event. It might be worth an examination.

Here again, if memory serves, I think it was located on the passenger's side behind footwell panel?

It's been more than a decade since I've owned these circa XJs, so don't take much of this to the bank.

[GeniusOfLove]

I imagine any decent code reader that can read more than the basic OBD stuff will tell you immediately what is wrong. Car thinking it's in D is a good bet.

Where are you based?

[Dave.]

Different car, but on the disco 3, of the brake light switch was iffy or one of the brake light bulbs was blown, out would cause similar issues.

/Straws firmly clutched, etc