Thread: Transmission fault/HDC fault

Thanks Guys,

Just pulled the switch apart and yes, there is dust from one of the contacts. I can't get any new bulbs from Landrover till tomorrow so I will wait till then to try replacing them all. I don't know if the bulb used was a genuine Landrover one or not as I got it changed at an independent who has been doing the work on my car since it came out of warranty.

This car has been very reliable for me for 4 years so it is a real disappointment to have this kind of thing happening but I am hoping that it is as simple as changing bulbs, I will also make sure the switch is seated properly and see if the lights are coming on at the right time if I can.

Cheers,

TimJ.

So if you changed the bulb in the D3 what ones(LED version/part #) did you get? I thought if you changed to LED it would disrupt the computer checks or something and u couldn't do it? I am keen to swap them cause I have gone through 3 globes in 7 months...

I swear by having a spare brake light switch in the glove box!

I know some owners replace their P21/5 bulbs with some variation of a LED and resistor, but for me, that is like wishing for an unplanned walk in the noon day sun.

I have considered replacing the P21/5 bulbs with the more common North American 1157 but so far have shied away from even that for fear of upsetting the monitoring systems. This is probably paranoia, and would solve the problem of the limited filament design life of the P21/5 bulb that is exaggerated by the fact the electrical system in the 3 runs at closer to 14 volts than 12 VDC.

The filament life of both the tail light and the brake light filaments in the P21/5 bulb is significantly less than the USA common 1157 dual filament bulb, (1000/250 vs 5000/1200 hours); brightness of the P21/5 is a bit more, (3/35 vs 3/32 candle power), but oddly, current consumption is less, (0.44/1.86 vs 0.59/2.10 amps).

It is the quest for efficiency vs maintenance trade off. It appears Land Rover regards your labour and expense to change bulbs as a worthwhile trade off in their quest for what they see as efficiency.

I got the faults mentioned, plus a couple more. After new battery, new ECU, and a couple of other things, it ended up being the high pressure fuel pump.

Cheers.

Originally Posted by bbyer

brightness of the P21/5 is a bit more, (3/35 vs 3/32 candle power), but oddly, current consumption is less, (0.44/1.86 vs 0.59/2.10 amps).

?? If I read that correctly, you're saying 3/35 is greater than 3/32? Surely it's the other way around?

Cheers,

Gordon

Too much short form I guess;probably should have written (3cp/35cp) and (0.44a / 1.86a) where cp is candlepower and a is amps.

What I intended to convey is 3 candle power brightness for the tail light filaments on either bulb and for the P21/5, 35 candlepower for the stop light filament contrasted with 32 candlepower of brightness for the brake light filament within the 1157 bulb. In reality, both are about the same, the real difference is in the amp draw. Incidentally I can find bulb specs out there that have somewhat different amp, candlepower, and hours values for the same generic bulb number. That bothers me as it tends to argue for the factory part number bulbs given that it seems there are not only manufacturing variations, but specification differences to what a given bulb may yield.

Both filaments in the P21/5 bulb draw less power than each of the filaments in the 1157. I figure the additional current draw of the 1157 would not be a problem for the conductors, but I am still afraid, (my paranoia?), of the contacts in the brake light switch.

I am not convinced that the contacts in even the replacement brake light switch are that much better designed. I wonder if even an extra short term load of about half an amp total on the brake light contacts would not adversely affect those contacts, particularly when the load is always make and break rather than sort of continuous.

Originally Posted by Timj

I haven't been so lucky, fitted a new switch yesterday and replaced the blown brake light that I didn't even realise was blown and today I got the errors more often than I ever have before. Previously it would pretty much fault once then be ok for a while, this time it went three times very quickly while on the Gateway motorway so I got off and headed back home and it still went another couple of times on the way home. Took the gear I had in the back out and into the Series 3 Game and off we went again, no faults in that one at least .

Is there anything else that can cause these errors together, Transmission fault, HDC fault, Suspension fault? It is always in the same situation, hill or slight rise, put the foot down to get up it and everything dies and goes into limp mode. Pull over, turn the car off for a few seconds, start it up and off you go again until the next time.

Thanks,

TimJ.

How old is your battery? Alternator &/or battery might be nect to check if it is not your brake lights.

Battery is pretty new so shouldn't be an issue. Charging seems ok but haven't really checked it properly. But today I changed all four of the brake/park lights for genuine Landrover ones that come in bags marked "Made in Slovakia" and are Osram. Two of the bulbs that were in there were Phillips and made in France and two were made in China with no brand. The one put in on Friday was one of the China ones and had a bit of corrosion so is very suspect. Took it for a drive and no errors so far, but it has done that before. Time will tell I suppose .

TimJ.