Transmission fault/HDC fault

**Graeme** · 10th October 2012, 10:02 PM

2.8 ohms equates to 51W at 12V and 4.2 ohms equates to 35W at 12V, both a long way from a nominal 18W with 51W equating to double the expected current draw if the meter is correct. What globe is in the left side?

Edit: The readings are crazy as 0.9 ohms equates to 160W!

**bbyer** · 11th October 2012, 12:42 AM

Originally Posted by Ashes

Took some readings with the OHM meter.

On the 200 setting on the meter
Repco globe reads 2.8 and 0.9 on the bottom contacts.
Genuine LR globe reads 4.2 and 0.9 on the bottom contacts.

Looks like the LR globe has higher resistance on one of the contacts. Not sure if resistance is altered though with age and use as the Repco globe must have been in a while and the LR globe is new.

I just measured two new unused genuine tail / brake light bulbs from my stock, both LR part number 264590, on two different ohm meters at the 200 setting.

I got similar numbers on both meters for both bulbs and close to Ashes numbers, that is 3.4 / 1.3 and 3.4 / 1.5 The 1.3 and 1.5 numbers were from the two different ohm meters so they were reading differently; each ohm meter showed similar numbers for each bulb.

I think that tungsten filament resistance is higher when hot and that is why the ohm numbers look low. Nominal filament current readings for a P21/5 bulb are supposed to be about 1.86 and 0.44 amps. That suggests hot resistances of about 6.5 and 27 ohms. The low resistance at cold start up is why I think filaments seem to burn out, (pop), right at start up. Bulbs do not seem to quit when operating, just when they first start.

The significant point however is that Ashes shows the Repco bulb as having a much different and lower number on one of the filaments; that suggests a quality control issue verses the LR bulbs that even across oceans seem to show similar numbers. I think this matters to the 3's monitoring systems.

**Graeme** · 11th October 2012, 05:41 AM

Originally Posted by bbyer

Edit: I think that tungsten filament resistance is higher when hot and that is why the ohm numbers look low.

I'd forgotten to consider that, thinking of normal resisters instead.

A 70% increase in initial current is quite significant but if its only 1 globe then its only 35%, although still quite detectable by the electronics.

**Ashes** · 11th October 2012, 07:20 AM

I forgot to mention that across the probes I had a 0.4 resistance so I guess this should be subtracted from my first numbers which would get them closer to Bbyers reading. Definately quite a difference between the two globes though.

**Graeme** · 11th October 2012, 11:30 AM

I wouldn't rely on any of the results if the meter is reading 0.4 ohms across the probes.

Edit: If its an analogue meter then it likely has a needle zero position adjustment screw.

**Ashes** · 20th October 2012, 07:22 PM

Took the car into LR on Monday and they adjusted the gear position indicator which they said was well out of normal range. No problems starting the car for the last 5 days.
I've had the HDC faults come up twice since then. Probably done around 30-40 starts without any faults though. I can live with the occasional fault but will continue replacing bulbs if the HDC faults get more regular.

**Graeme** · 20th October 2012, 08:20 PM

Do you know what led them to check the gear position indicator?

**Ashes** · 20th October 2012, 09:34 PM

Probably some of the info that I provided that the car would usually start if I shifted from park to neutral. I was convinced it was a starter solenoid problem but hopefully this fixes the starting problem for good. If it fixes the start problem I can then start again on the HDC faults again.

**Ashes** · 29th November 2012, 09:03 PM

Car got to the point where it would not start. Just a clunk. It did this while being serviced and it was confirmed that it was a starter problem.
Replaced the starter motor on the 21st Nov and no starting problems or warnings since then. I'll report back in a month or so if no further problems or earlier if they return. I have the old starter so might have a look at the solenoid out of curiosity and if stuffed, get the solenoid replacement kit so I have a working spare.

**Timj** · 30th November 2012, 01:07 PM

I thought I would come back to this thread and give a final report on what has been happening with mine. From earlier posts you would know that mine had all the dreaded errors and it wasn't caused by brake bulbs or the brake switch though these were replaced. The whole story is as follows, could be a bit long -

The fuel gauge started to play up back before Easter this year, I was not sure when I had last filled up or if my wife or daughter had filled it but it didn't seem to be dropping as fast as it should. Then one time when I got in it was showing full and again I thought that someone else must have filled it. On my way home the next night I pulled onto the freeway only to have it error and drop to the bump stops at the top of the onramp. A number of attempts to restart it did not get far. Towed off the freeway, checked by RACQ, more attempts to restart and then the next day towed to the mechanic.

I am sure he also tried to start it many times and eventually he worked out that there was no petrol in the main tank despite the gauge showing full. He pumped petrol across from the auxilliary tank and it started again. So out with the tank and replace the rear sender as it was showing errors, front seemed ok and is impossible to change anyway. Car still came up with errors, going into limp mode on me regularly and in fact being quite dangerous to drive. Errors now were showing low fuel pressure in the low pressure side and this was confirmed with physical tests so the pump in the tank was replaced and the fuel filter was replaced.

Still no go, went fine for the mechanic but as soon as I tried to drive it errors and limp mode. Once the mechanic had driven it around for two days including a trip to the other side of Brisbane with no errors, I hopped in and it faulted on the way out of his driveway. After reading about brake bulbs on here these and the switch were all replaced with no result. The faults were now showing low fuel pressure in the high pressure rail and tests indicated that the pressure regulator was faulty. Of course this can't be replaced by itself, it is part of the high pressure pump. I ended up sourcing one off ebay in Latvia for about $900 delivered and fortunately it was the right part and the service was great.

However after this was replaced there were still errors coming up in the fuel system and the same limp mode. The mechanic tried one last thing which was to replace the fuel rail but that still did not clear it. The last ditch attempt was to reflash the ECU. After this was done the car has been running perfectly for a couple of months now.

The one thing that still hasn't been working properly is the fuel gauge, I really don't want to pay for a new tank just to get the gauge working, I have the aux tank and have been resetting the odometer when refilling and then refilling from the aux after about 600k and then filling up again before too long. This worked fine until a recent trip where I must have had an airlock or something and though I thought I had filled the main tank I obviously hadn't and at about 300k we went down the the bumpstops again and all the errors came up. This time I thought about it after trying to restart once and pumped fuel in from the aux. After a couple of tries and some priming away we went with no more issues. And again it has been fine since.

So my conclusions are that due to the many initial attempts to restart with no fuel in the tank that the pumps were probably damaged by running them completely dry. I can only assume that the constant errors thrown in with inconsistent readings from the fuel gauge caused a glitch in the ECU that required the reflash to fix it. This stupid set of errors comes up for so many situations that it is pretty much impossible to know what is the root cause without access to a fault reader and knowledge of the fault codes. It is also possible that I didn't need to replace anything, that a reflash straight away may have solved the problems but I don't believe so since physical tests were backing up issues with fuel pressure.

And a last thing, has anyone actually replaced the sender at the front of the tank? Apparently it is possible if you have extremely long, extremely thin arms but I have not found anyone who has actually done it.

So at the moment it is running well, apart from the gauge, but I spent probably 5 months unable to trust it to take us on a trip which was very frustrating. But for some reason I still love the car.

With any luck that story may help someone else with issues

.

Cheers,

TimJ.

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