Freelander 1 L series HDC warning light

I'm hoping for some tips on how to deal with the HDC warning light, apart from gaffer tape over distracting light! There are no other lights showing just HDC. I've had a look at all four wheel sensors which seem to be physically OK and I'm at a loss to know where else to start looking.

My Hippo is a 2000MY which I think is pre OBD. I realise that HDC uses the ABS system which seems to be still working. I know that it also uses wheel sensors and reluctor rings on the drive shafts, all or any of which could be faulty. Is there any easy way with a multi meter to check operation of wheel sensors? What does the dashboard warning light actually indicate?

I've also checked the first gear sensor wiring which looks OK but I have disconnected my reversing light switch and changed it to manual operation. I don't know if this is likely to have an effect with HDC operating on first and reverse. I did it because a new Rev switch didn't cure the "no-lights" problem and I tow trailers regularly. It is very handy to be able to switch on yer reversing lights when hitching up the trailer or locking gates in the dark.

A step by step diagnostic approach from an egg spurt would be really useful and greatly appreciated.

Otherwise the old girl is still going great guns albeit on the second engine in 145k miles.

Rave gives the following reasons for just the HDC light to be lit:

"Brake lamp relay fault"
"Implausible gear position input"
"Sticking throttle"

So its likely to be the 2nd option given you have "bespoke" reverse wiring!

You can have the codes read, the L Series is not ODBII compatible, so a cheap dongle won't work, but Freelander specific tools such as Hawkeye, i930, Lynx etc will read the codes. Or take it to a garage that can read them.

I've now replaced the Revo light bulbs with very bright LEDs which are brilliant for my particular needs. I wouldn't want to go back to gearstick operation.

Thinking about the cause of the warning light, it didn't come up when I first altered the wiring but then I probably didn't operate the HDC switch at that time. Once activated is the only way to remove the warning light display by using testbook or similar?

Looking at the original cause of "no reversing lights", replacement of the switch didn't help but connecting the wires at the switch did operate the lamps. I'm assuming that the switch is operated by movement of a gearbox shaft or lever and that there is for some reason, insufficient movement. This might explain the sometimes reluctance to engage reverse?

Not sure if the sort of fault you have would need to be cleared by diagnostics or would just clear if the problem were resolved.

I have heard that the PG1 gearbox can be reluctant to go into reverse - mine is true to that and needs a good firm push to engage it - sometimes it takes a second push after the first attempt results in a cringe!

The light would normally be illuminated whilst the fault was stored.
I agree that the 'manual' operation of the reverse lights would well cause an implausible situation
I think you need to get the code stored reset then consider other methods of activating your reverse lights.
If you MUST have manual operation -
the easiest option would be to use a relay with the coil fed from the existing reverse lighting circuit (from the reverse select switch) via a diode to ground. The heavy side of the relay would activate the rev lights via a take off from the existing rev light fuse. That way the feed to the ABS ECU is maintained.
To activate manually, then the relay would simply need power applied AFTER the diode (and also VIA another diode in the manual switch circuit. This way the existing abs circuit does not sense implausible operation, yet will still work correctly.
Don't forget you would also need a back emf diode (flyback diode) across the relay coil.
Sounds complex, simple in practice. - you need a relay (20A is a common size) and 3 diodes - 1N 4001 or similar.
Joe

Joe
Thanks for your response and solution.
It sounds way too complicated for me although I can work a soldering iron.
I wondered why nobody had thought of using the Rev lights as work lights. Now I know!

Having said that, I find that the work light solution is more use to me than HDC at the moment but I don't like to have anything not working so maybe I'll think about it.

Happyhippo said:

Joe
Thanks for your response and solution.
It sounds way too complicated for me although I can work a soldering iron.
I wondered why nobody had thought of using the Rev lights as work lights. Now I know!

Having said that, I find that the work light solution is more use to me than HDC at the moment but I don't like to have anything not working so maybe I'll think about it.

Click to expand...

I will do you a quick diagram if you can hang on till tomorrow evening ? (out all day tomorrow) - it is easy to do once you see it.
Joe

Hi everybody.
Im another happy owner of a hippo 2000, have got exactly the same problem but didnt make any particular electric change so its supposed to be everything original.

What i did change is the accel wire, and light seems to me that appeared after that.

I found a diagnose device thats able to read my ecu (app for android: MEMS Diag) and find out the error codes as follows:

Status byte 1, bit 0 (set) engine coolant temp sensor faulty
Status byte 2, bit 5 (set) unknown error
Status byte 2, bit 7 (set) Throttle pos sensor (TPS) circuit faulty

I reset all the error codes but the light still is there and the error codes are not appearing again. Checked again even after a long drive but nothing happens. Any good idea other than taking the bulb from the dash?

Brake lights work perfect, reverse lights also... And ABS seems to work as well.

Thanks everybody
Have a good one.

Andres el Brujo said:

Hi everybody.
Im another happy owner of a hippo 2000, have got exactly the same problem but didnt make any particular electric change so its supposed to be everything original.

What i did change is the accel wire, and light seems to me that appeared after that.

I found a diagnose device thats able to read my ecu (app for android: MEMS Diag) and find out the error codes as follows:

Status byte 1, bit 0 (set) engine coolant temp sensor faulty
Status byte 2, bit 5 (set) unknown error
Status byte 2, bit 7 (set) Throttle pos sensor (TPS) circuit faulty

I reset all the error codes but the light still is there and the error codes are not appearing again. Checked again even after a long drive but nothing happens. Any good idea other than taking the bulb from the dash?

Brake lights work perfect, reverse lights also... And ABS seems to work as well.

Thanks everybody
Have a good one.

Click to expand...

Interesting post!

I'm pretty sure MEMS Diag has not been discussed on here before, I can not recall hearing about it. It looks interesting. Not much info or documentation about it though.

I take it you have the K Series petrol engine?

The HDC warning is generated from the ABS ECU - not the engine ECU. So MEMS Diag will not be talking to the ABS or reading/clearing its codes.

I have a '99 diesel. While no generic ODB tools will talk to the engine, I have tested with a friend's device which would talk to the ABS - so might be worth your while trying a generic device if you have one or know someone that does. It would need to be a device that talks to ABS, ODBII spec is just for engines and primarily specified so that emmisions can be monitored (as I understand it).

As GG says do you have a petrol K series car. If so then slacken your throttle cable at the the throttle body as tightening it will cause HDC light.