Car doesn't start & shows 'transmission malfunction' on the dash

Question

I have a 2.0 TDCI Ford Focus 2008 MKII.

I hadn't driven it for a few days and when I did the central locking wasn't working but all other electric worked fine and the car ignition engaged but wouldn't start.

I removed and charged the battery, The car started fine and drove fine for 30 minutes after which I parked and left, The next day, the car was completely dead! No electrical activity at all.

I charged the battery, ran it again for 40 minutes to confirm the alternator hadn't died. It worked fine. Left it over night, and again completely dead.

Charged it again, ran it, then disconnected the battery negative terminal overnight, the next day re-connected and it worked fine so I figured the engine was dis-charging the battery.

I got a multi-meter and checked and discovered when hooked up, the engine was pulling 16A from the battery, killing it in under 2 hours.

I went through the primary and auxiliary fuse boxes pulling fuses to try and isolate the circuit causing the problem, no change. My suspicion is still potentially the alternator is the problem. Any thoughts on that would be appreciated.

After all that, the car threw out a 'transmission malfunction'. All electrics work but the ignition doesn't engage, so I can't start the car, and when I turn on the headlights i hear a single click from the auxiliary fuse box under the glove compartment.

Any ideas?

Thanks

Answer 1

If you checked all the fuses, the alternator indeed might be the problem. You might also disconnect the plug going from PCM to alternator which is required for smart charging feature. Without it the voltage regulator should fallback to default, constant voltage of 13.7V and dashboard indicator should be lit. Check again if it's still discharging. Also maybe you have some additional equipment added, like the amplifier for car audio or non-original car alarm? BTW 16A x 12V is a huge amount of energy, almost 200W of heat has to be dissipated somewhere. That might cause serious fire hazard, better check this ASAP.