O

overdraft

Member
Hello all , quick question.

My 2003 4.4v8 that I haven't been driving has developed the following fault.

I have asked this before and thanks for the replies but still haven't reached a conclusion, as I don't want to have to drop out the box if possible.

The gear selector on the console is cycling and displaying all operations of the box I.E park , neutral , drive , reverse etc.

The green display on the dash is intermittent and won't display neutral or park, it will sometimes will on repeatedly turning the ignition on and off.

Sometimes the car will start by holding the key against the start position and after a few seconds it will start.

I got under my car on high suspension settings and looked at the box, there is a lead that travels over the box from the drivers side and connects to the box on the top passengers side, with a quarter turn connector, I released it and sprayed with contact cleaner, still the same.

From this is my gear selector internal, I thought from posts they are external, an easy swap.

My question is prior to dropping the box, is how come the indicator on the centre console is working fine surely they used the same signal ?

Is it somehow related to a micro switch around the selector gear lever itself, I had a range rover technician plug in and check it over and it's the box was not seeing park , or neutral and was of coarse in limp mode I.E. 3 rd gear, which explains why I thought the box was low on oil as it felt like a slipping clutch pulling off.

Any box or tech guys reading your advise would be helpful.
 
The sources of the two signals are entirely separate.

The display on the console showing the selector lever position receives its signal from a simple sliding contact switch built into the lever assembly itself which then illuminates the relevant LED.

PCBfront_zps04a0bdda.jpg


PCBrear_zps9d03d4d7.jpg


The display on the dash, on the other hand, comes from the ECU which in turn gets its signal from the inhibitor switch bolted to the RH side of the transmission casing.

If your dash display is behaving weirdly then you have an inhibitor switch fault. If you disconnect the C1452 connector again that you had apart before (i.e. the one mounted in the bracket bolted to the top of the bellhousing) you can trace the fault yourself just using a multimeter to check the continuity between the +ve pin and the remaining pins according to the table below. (Note that the connections shown in RAVE are incorrect).

InhibitorSwitch1.jpg


InhibitorSwitch2.jpg


InhibitorSwitch3.jpg


The switches are stupid money (even second-hand ones go for £150 - £200) so definitely worth checking first before you replace it. You don’t need to drop the transmission to do this as it’s external (the GM 5L40-E used in the TD6 has the inhibitor switch inside the sump).
 
Bemble said:
The sources of the two signals are entirely separate.

The display on the console showing the selector lever position receives its signal from a simple sliding contact switch built into the lever assembly itself which then illuminates the relevant LED.

PCBfront_zps04a0bdda.jpg


PCBrear_zps9d03d4d7.jpg


The display on the dash, on the other hand, comes from the ECU which in turn gets its signal from the inhibitor switch bolted to the RH side of the transmission casing.

If your dash display is behaving weirdly then you have an inhibitor switch fault. If you disconnect the C1452 connector again that you had apart before (i.e. the one mounted in the bracket bolted to the top of the bellhousing) you can trace the fault yourself just using a multimeter to check the continuity between the +ve pin and the remaining pins according to the table below. (Note that the connections shown in RAVE are incorrect).

InhibitorSwitch1.jpg


InhibitorSwitch2.jpg


InhibitorSwitch3.jpg


The switches are stupid money (even second-hand ones go for £150 - £200) so definitely worth checking first before you replace it. You don’t need to drop the transmission to do this as it’s external (the GM 5L40-E used in the TD6 has the inhibitor switch inside the sump).
Click to expand...



Thank you for the comprehensive reply at least now there is a definitive process to resolve the issue.
 
Look at the loom, I think it goes over the top of the gearbox and rubs if my memory of other posts is correct.
 
Ok so I got access to the connector from the top side of the engine bay, opened it up and checked the connections all seemed ok.

I removed the gear selector switch and bored out the stud fasteners and opened it up, the four prongs on the base where coated in a white grease, so I bent them all up with a screw driver in an effort to get a better contact, also scrapped all the copper guides on the other part, put it back together and riveted the two parts together and built it back up.

Turned on the ignition no dash inductor but no the car will start , tried it four times in a row started each time, but no display P N R D etc, cycled the positions covering the brake pedal and it thumped into gear, neutral , reverse etc.

It's it definitely the switch at fault prior to shelling out £150 for a second hand one ?
 
overdraft said:
Ok so I got access to the connector from the top side of the engine bay, opened it up and checked the connections all seemed ok.

I removed the gear selector switch and bored out the stud fasteners and opened it up, the four prongs on the base where coated in a white grease, so I bent them all up with a screw driver in an effort to get a better contact, also scrapped all the copper guides on the other part, put it back together and riveted the two parts together and built it back up.

Turned on the ignition no dash inductor but no the car will start , tried it four times in a row started each time, but no display P N R D etc, cycled the positions covering the brake pedal and it thumped into gear, neutral , reverse etc.

It's it definitely the switch at fault prior to shelling out £150 for a second hand one ?
Click to expand...

So now the car starts, but still no display on the dash...but you did get a drive gear....does it drive as it may default to 3rd gear failsafe if the switch is duff...Bemble will confirm or refute this! :D

certainly seems to look like you switch is iffy, Bemble is the defacto genius on the L322 Gearboxes
 
Are you in the UK, overdraft?

I have an L322 5HP24 inhibitor switch lying around which functions perfectly but the plastic casing is broken where the cable enters

Wiresexposed.jpg


making it unsuitable for permanent fitment, but you’re welcome to try it to see if it fixes your problem and then send it back to me - it would just cost you the postage. At least then you’d know if it was worth spending the money on a replacement?

Another thing you could try is to measure the continuity of the switch up at the ECU end in case there’s a problem somewhere in the rest of the transmission wiring loom

TemperatureSensoratECU.jpg


C1835_zps2d1c6330.jpg


C1835.jpg
 
Yes the car does cycle through all gears with a thud , also it displayed the trans error.

When I turn the ignition there's no green dash display but the car will start and covering the brake it will select the gears but with a thud and a jerk of the vehicle.


Are the switches model specific or does the diesels use the same type, as I now a local dismantlers has a diesel.
 
overdraft said:
Yes the car does cycle through all gears with a thud , also it displayed the trans error.

When I turn the ignition there's no green dash display but the car will start and covering the brake it will select the gears but with a thud and a jerk of the vehicle.


Are the switches model specific or does the diesels use the same type, as I now a local dismantlers has a diesel.
Click to expand...
Different Gearbox entirely...

Petrol uses ZF and the Diesel a GM
 
Ok, perfecta petrol one it is then. If the offer still stands to borrow yours to check the system over that would be great,
 
Last edited:
overdraft said:
Ok, perfecta petrol one it is then. If the offer still stands to borrow yours to check the system over that would be great,
Can you send me an email to XXXXXXXXXXXXXXXXX and I will send you my address and payment .
Click to expand...
Remove yer email addy buddy and put it in a PM to Bemble.....
 
overdraft said:
How to you pm on this forum, tapped name got drop down box but no send private message?
Click to expand...

drop down on mine gives me the option to "private message"

if not go onto their profile page and at the bottom is says "private message"

or something along those lines lol
 
Good morning,

I've a quite similar problem even if not exactly the same.
Sometimes (and more and more often), when I put the key in I get a "TRANS FAIL" message on the dash and the gearbox is in the secure mode (4th gear only I guess).
It happens when I put the key or when I move the gear selector the first time. When the massage is here, I have "a thud and a jerk of the vehicle" when moving the gear selector as described above.
Putting the contact on / off / on once or several times generally makes the message disappear. Or sometimes I must drive few hundred meters and the put the contact off and on again to have the message disappearing.
When the message is no more there, the gearbox works perfectly well and the message never appears again when driving. Until the next time after having stopped for several hours.
I've checked the default code with a iCaresoft i930 and got "P0705 transmission range sensor circuit malfunction prndl input" that means I fear an issue with the inhibitor switch. But how to be sure and how to explain that the fault doesn't come all the time?

Many thanks for your input,
Pierre
 
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