On my 2008 LR2 this is the second occurrence of this no-start problem. 12.4V on battery, all lights and systems seem to be at full power. Battery connections are clean and tight. Open inserting the handset and pressing the start button there is a 'Click-click, Click-click, Click' coming from behind the glove box (right side), and another single click comming from the drivers side footwell. Have checked starter fuse (F15) and swapped Starter relay (R1) with no change. The shift lock releases and in order to get the handset to release from it's dock the shift has to be in P or N then the start button has to be pressed. At which time the dame 'Click-click, Click-click, Click' occurs from the same locations. This had happened a year or two ago and all I did was to check all the fuses and relays and wiggle them all, but was never really able to find anything wrong. (By the way, I've repeated the check and reseat all the fuses and relays.)
Any ideas?

 

The starter itself? It's just under the bash plate. Google how to give it a crack with a mallet? If it works, time for a new starter.

 

Okay, I've accessed the starter and verified that when the starter solenoid when tripped (from power to solenoid post) the starter cranks. Now I see there is something called a 'I6 3.2L Petrol -Start Control Unit' well hidden above the drivers (US Version) footwell. It is very well hidden. It looks like both the upper snd lower dash elements have to be removes (including the lower air bag).

what the heck is a "start control unit" and why do we have to download it's data before replacing it? WTF!

anyone???

 

Research JLR SDD and a mongoose cable right on this forum.

 

You're going about this the wrong way. This not your cousin's 55 Chevy. This car is fully computerized and if you ask it, it will tell you what is wrong. Take it to an Autozone or similar store and ask them to scan it, then post the resulting codes here. They will usually do that for free.

 

I think you may have overlooked the part about NoStart. I pretty much understand the part about the 55 chevy. Ive traced it down to lines C1E104-C4 going to O_S_STRT and C1E104-K1 going to O_S_STRTN on the ECM. Those lines go to the line and load sides of the starter relay, and when I measure the voltage on the 'line' side of the relay it only goes up to ~11.7V even though the battery voltage is ~12.4V. My OBD reports nothing and the FSM says to have a LR scan tool read the codes.

 

Standard OBD will not tell you anything about this, because it only deals with generalized codes, not the LR-specific codes. All the OBD codes start with a P and only have three or four digits. The codes related to the start control unit start with a B1024xx, where the xx can be 51, 81, 87 or 96. Each one has a different cause and action to take. This is why you need to get the system read by a scanner that understands the LR modules. If the start control unit needs to be reprogrammed, you need the JLR SDD software and the Mongoose cable (or go to the dealer or a mechanic who has it) as well as a Midtronic PSC-550 power supply that will keep the vehicle powered while you do the reprogramming (otherwise you risk bricking the system). If the start control unit has a hardware failure, it gets hairier, so let's not go there for now.

The 11.7 volt reading suggests a battery that is not fully charged. This will cause the symptom you are seeing, and a failing/failed starter will discharge the battery to the point where it won't turn over, period.

When you go get the car scanned, have them test the battery to make sure it's in good shape. If you can put a battery booster on it and it turns over, you may have found your culprit, because the starter may be failing but still turnover with more juice. Replacing the starter is an easy DIY job (one of the few on this car that is that way).

Finally, I had the exact same symptoms on my 2008 as well. It was the starter. Good luck!

 

Well, we sorted it out but, as may be expected, it still makes little sense. With all the tracing of wiring diagrams (they have started making them easier to print, but not to understand) we were able to sort it out to the steering wheel locking mechanism. After reading several posts and thinking that couldn't be it we removed the lower steering column cover (Pain in *ss) and tapped the housing of the mechanism and wha-la it starts now.
Curiously the steering wheel was never 'Locked', and now I have noticed a lock cycle on startup. I never noticed that before.
So apparently the logic checks a whole bunch of things, shift in P or N, foot on brake, fuel rail pressure, ignition ready, steering wheel condition, air conditioner off, radio on proper channel and seat warmers off, and probably a whole bunch of other stuff, and then it allows everything to work. If the little plunger in the steering lock mechanism doesn't cycle properly it can't respond the way the logic gods want, so so joy. Not really a good design for an off road vehicle. Still after 14 years and 220,000 miles I'm glad it is good to go.

Now, about that rear differential................

 

Interesting. So there was absolutely no message before on the dash display re the steering lock? In addition, for the future, get familiar with the different immoblizer red light flashing cycles on dash. It definitely can give you a heads up that something is amiss.

 

Now that is a weird one. Never seen that before, but I do know that squirting some clear lubricant (not WD-40) in the lock housing helps to unstick it so you don't need to remove it altogether. Catch is you may have to drill a small hole to get the lubricant in there. Congrats!