Hello everyone brand new to the forum not so new to Discos. I'm trying to get my current D2 running again and am getting it to crank, but it won't start. The tach doesn't move when cranking making me think crank sensor so I replaced that with one from autozone, but still no dice. The only thing its giving me is a P1842 and P1843 code, which I've read could be caused by low battery, but its a brand new battery so that rules that out. I'm thinking tomorrow I'll take the crank position sensor out and make sure its clean, but beyond that I'm a bit at a loss for what to try next. It's got 117k miles and was pretty well taken care of before I got it from what I can tell, but I imagine age is taking a toll on the various parts so I'm prepared to replace whatever I need to. Also as a side note does anyone know what size the nuts are that hold the crank position sensor in? I managed to round one off trying to take the new sensor out to clean it.

 

Those two codes are transmission control unit codes.
P1842: CAN level monitoring
P1843: CAN time-out monitoring

Basically it means that there is something wrong with the connection to the ECU and transmission module. This could have been a temporary fault caused by a low battery, or it could be a wiring or plug issue.
These codes alone shouldnt cause a no start issue, so the problem likely lies elsewhere. Unless there is a major wiring or even ECU issue causing both the codes and no starting.


My tach doesnt move when cranking, and only moves after the engine starts. How long ago was it since the last time you ran the disco? Is the fuel in good condition? I would check fuel pressure.

 

What about the Inertia Switch? If it is tripped I believe you still get crank, but no power to the fuel pump. It could also be a faulty fuel pump relay. There are numerous other possibilities but I would try those checks next.

 

It hasn't run in probably 4 months or so, but I imagine the fuel is still okay, or at least okay enough to run. It's not getting power to the fuel pump (according to a non land rover mechanic) though I'm going to double check

 

I reset the inertia switch and still no luck. The switch could be bad I suppose, but there's nothing visually wrong with it and it looks pretty clean like it may have been replaced somewhat recently. I'll check that and the fuel pump relay next.

 

So I swapped around some relays to test if it was the relay itself for the fuel pump and still just crank no start

 

Has the ECU Immobilized the engine (thinking that someone has attempted to steal the car)? This has never happened to me on my Disco, but several times on my P38. On the P38 it tells you that on the instrument panel. I suspect it would on the Disco as well, but I don’t know.

 

I don't think so. My key fob still unlocks the doors, or at least the drivers side, and I don't see the alarm light flashing otherwise. I don't see any indicator for it on the instrument panel either

 

The video is me trying to start the car showing the dash in case its helpful

 

I swapped the new crank position sensor with an even newer one and still no luck. This may be a dumb question, but does the shield need to be on for proper function? I wouldn't think so, but maybe that's what's been wrong the whole time. Other than that I've taken out the passenger compartment fuse box to make sure nothing is wrong there and it all looks fine. The ECU and all plugs there look fine as well. I've got a third crank position sensor on the way just in case I got two bad ones from autozone, which is possible I suppose, they once gave me 5 bad alternators for a different vehicle. I'm half tempted to have it towed to a shop at this point, but that will be a hefty bill I'm sure. Any suggestions on what else to check in the meantime would be greatly appreciated.