I checked for codes with an aftermarket Wifi based OBD reader - now my car won't start. I get the dash indicator lights coming on with the ignition, but when I turn the key I hear a single click, the dash lights go out then come back on and then I hear a weird whirring sound from beneath the dash. Obviously the car doesn't crank. AI says to check some fuses - I have yet to do that as to add insult to injury I am locked into my apartment as the lock has seized. I am waiting for the locksmith as I write this. In the meantime anyone know what likely is wrong?

 

My first instinct is the battery. Did you leave the code reader in place? I have one of those $15 eBay code readers and even with the car off it draws enough current to bring the battery voltage down over a few days.

If you did not leave the code reader in there for days you could check fuse 25 that feeds power (always on) to the OBD and check fuse 32, switched power to the OBD. Neither of those should stop the car from starting so unlikely, but the only fuses directly related to that OBD port.

 

Checked battery - 12.2 V, Checked following dash fuses visually : F31,25,32,17,2 all good (Gonna check again with a multimeter when I get home from work later today - CHecked under bonnet fuses F2 F8/10 all good. Tried ECM reset procedure - disconnect battery - hold terminals together 10 seconds then reconnecy Ign to II for 30 seconds, off for 5 seconds then try crank - still no crank. Shows a DSC fault and there is a clicking every half second with the panel lights dimming in unison. Not sure where to go from here. Thinking of having it towed to the dealer.

 

Are you getting a rapidly flashing security light on the center console? The OBD could have triggered your immobilizer, some how. If you have no rapidly flashing security light then change the battery in your key fob or try using your second key. If the key fob is dead (or the key is worn down) it won't communicate to the car to start - or the car won't recognize the key fob.

 

12.2 is near dead

 

I only saw this thread now: "YES" on all 3 comments made above:
Check starting the car with all key you have (on one of them the transponder may have died)
But more likely: Your battery is dead. 12.2V sounds very low. How much does it measure, when you have the ignition in the ON position and when you have the driving lights switched on at the same time? If you don't want to buy a new battery just now, buy or borrow a battery charger. If you buy one, get a 10A or 15A CTEK charger.

A code reader (especially cheap ones) normally do only READ codes - they should not modify anything...

 

The car was cranking fine until after I used my OBD reader. I think the issue might be something other than a flat battery.

 

The code reader plugging in/out of the OBD port is unlikely to cause problems. I believe these cars only have 6 pins populated in the OBD port. 2 grounds, 1 constant power, 1 switched power, and 2 communication bus. If the communications bus was somehow damaged the engine will still start.

When you used the reader to check for codes what did it tell you?

 

All I got was the P1111 (all systems good) code.

 

I repeat 12.2 is near dead. What does it read as you try to start?

 

I, too, repeat: Do measurements under load, as I described above. / and if you don't want to buy a battery right now, charge it at least.
I, too, once thought, my battery is fine, when it had about 12.5V - but it was dead and the cause of the issue...

 

As well as the Controller Area Network (CAN) there's also two wires for the Standard Corporate Protocol Network and another one for the Serial Data Link. Nine in all

 

I am alone so it is hard to do the load test. I have decided to conserve what battery is left so i can unlock the car and will get it towed to the dealership who can do the definitive testing for me. I don't have facility to charge the battery as it is parked in my apartment basement without access to a power point.

 

About your parking situation: Can you borrow a battery from a mate. It does not have to be the exact model, as long as you can connect the terminals (be aware that some batteries have plus and minus swapped, hence, make sure to connect - to - and + to plus).

No problem to do the load test yourself: just turn the key into the ign.-ON position (without starting), leave it there, turn on the lights and go to the battery and measure.
As I think it is very likely that your battery is dead, the money you intend to spend for towing would be better invested in a new battery....

 

The tow won't cost me anything as it is covered under my roadside assistance package. There will be a slight charge for diagnosis at the JLR dealer but I am prepared to pay this to make sure I have correct diagnosis as AI has suggested the issue might be with the OBD reader corrupting my BUS system.

 

OK.
But one more thing - I forgot to write the obvious: You can remove the battery from your car, move it into your accommodation and charge it there...