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The only place for a coil spring is up Zebedee's arse
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Gilbertd wrote:

Leak in the exhaust manifold you'd hear and it didn't sound like it had one on the video. You can at least check you've got ignition switched 12V arriving at the sensor connector.

Tested it. 12V does arrive. As well, when the engine is turned on, the sensor, still hanging under the car, heats up..

So I'd definitely say it's a simple ignition problem... Or at least I'm hoping!

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Managed to find a coil pack and an engine ECU from a mate on another forum for €50...

If that and the new plugs and wires, and a reset of the adaptive values don't cure the problem...then cats it is...

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Cats wouldn't have any effect as the lambda sensors are checking before the cats. Only US spec cars have post cat sensors to check that they are working. You can't simply swap an engine ECU as it is keyed to the BeCM, you will need at least a Nanocom to sync the two (I think but can't swear that a nano can do it even). Coil packs fire pairs of cylinders, one on each bank so if you had a coil pack going down, it would effect a cylinder on each bank. Looks like that just leaves the HT leads then.

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Nano will sync BECM to ECU. Did an ECU swap on mine recently.
On a Thor, read code from ECU (3 or 4 digits) and enter into BECM. Save settings in BECM.
While in ECU with Nano, make sure rest of settings are correct for car and reset adaptives.

Gilbertd wrote:

You can't simply swap an engine ECU as it is keyed to the BeCM, you will need at least a Nanocom to sync the two (I think but can't swear that a nano can do it even).

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RRHSG wrote:

Managed to find a coil pack and an engine ECU from a mate on another forum for €50...

If that and the new plugs and wires, and a reset of the adaptive values don't cure the problem...then cats it is...

Yes, but a mate will come with a Nanocom...I'll stick the leads, reset values and check. Then change the ECU (yes you need the nanocom to mate the ECU and the BECM) and reset again.. Looks fun

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Orangebean wrote:

Nano will sync BECM to ECU. Did an ECU swap on mine recently.
On a Thor, read code from ECU (3 or 4 digits) and enter into BECM. Save settings in BECM.
While in ECU with Nano, make sure rest of settings are correct for car and reset adaptives.

Hey Orangebean,

Is it really that simple ? I mean sounds like it's a 3 click job to enter the code in the BECM...

I have never used a Nano so wouldn't want to brick the becm...

Any precisions or tips would be greatly appreciated !

Thanks a lot

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Found this on another post, is it correct ?

Remove old ECU,

Refit new ECU,

Before trying to start it, with the nanocom, key in Pos II, Go into P38 -> Motronic -> Motronic -> Settings. Arrow across to the 3rd page and at the bottom is 'Immobilisation Code' write this number down.
Then exit out back to the list of ECU's.
Turn ignition OFF (BECM responds best to diagnostics with ignition off)

Go into BECM -> Settings -> Alarm. You should get 'DIAGNOSTICS MODE' on the message centre. Don't worry if you don't just yet as long as you can still talk to the BECM!

Arrow across to the last page and you will see a box with 'Immobilisation Code' above it.

Tap the white box, and delete the original digits. Write in the digits you wrote down from the settings in the engine ECU.

Press Red X once,

Press 'Write Settings'

You'll get a confirmation.

Then exit out and 'DIAGNOSTICS MODE' should disappear from the dash.

Done.

Then put key back in ignition, and start her up!<br/>

Hope this helps..

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Looks about right. I kind of followed my nose through the menus, so not sure how many pages you click through etc, but your method above in terms of key position 2 , Motronic first, write down code, key off, into BECM alarm settings, enter new code, write settings is correct.
Don't forget to reset adaptives. Wouldn't hurt to clean contacts in connectors before you fit replacement ECU either.

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cheers.

I also found a "learn security code" just above the "reset adaptive values" button...

Could it be the magic button that replaces the procedure we're talking about ?

Don't worry, I'll reset the values, and check everything. I have the nano for a couple days maybe 3, so I'll check as much as i can.

Just hope that if i have to change the coils, it wan't take me 2 days to do... !!!!

I'll stick in the new ecu first, learn code, reset, and test drive
if not enough, i'll change the HT leads. Reset values.
If not enough, coils and reset the values.

After that, the 02 sensors, plugs, coils, ecu, leads will be new or "know that it works" second hand.

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Don't touch that button!!!
It's for the Motronic on a Disco 2 which works differently...
No need to reset adaptives after changing leads, coils, plugs. Only relevant for fuel/ air related items.

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Ahaha I thought so too. Had it been in the BECM menu, I might have tried it. But being in the motronic menu it does'nt make much sense for the engine ECU to "learn" something..

I won't touch it. I promise. Sorry for the scare !

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The 'Learn Security Code' button does nothing on a P38... even if you press it, it won't make the ECU self-destruct or anything stupid like that.

The same Motronic module in the Nanocom is used for both D2 and P38, so if you have a D2 to reset the security code, then you can just press the button and it will do it.

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Alright big day today

Swapped the Ecu, reset, nothing.
Replaced coils and leads, reset, nothing.
(a mate of mine had done it once on another p38..he did mine, coils and leads, in 20 minutes, without removing the plenum and with all the lpg stuff on top. Thought I'd mention that !)

Reset, nothing.

The worst thing is...problem has now switched sides without any reason. It's now the bank a sensor that inevitably drops to zero after 10 minutes of working fine.

So we spent the next hour swapping sensors (2 new ones from 3 months ago,and the original ones from a year ago that I thought were faulty) , and resetting values.

...still the same...

So far are OK, or new :

Plugs
Wires
Coils
Ecu
Sensors
Wiring
No exhaust leak
No manifold leak

I'm losing my mind...

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Hmm, interesting. Seems to me that the only thing you have changed that could cause it to move is the ECU. Is there any possibility that the contacts in the plug aren't making a good connection? Have you tried a good squirt of contact cleaner and plugged and unplugged it a few times to make sure everything is clean?

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I'm thinking maybe after plugin and unplugging it a few times (when i was checking the resitance and continuity of the wires) maybe I damaged one of the wires..

Couldn't I just rewire the 3 wires (he 4th goes to the fuse box so i'll leave it alone) form the sensor connector under the car, straight to the connector on the ECU ? A sort of "new loom" for testing purposes ?

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Yeah I cleaned them, maybe not thoroughly enough though.. I didn't plug/unplugged it a few times as you said..

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RRHSG wrote:

Couldn't I just rewire the 3 wires

You could but that will just take the wire as far as the connector in the plug so if the iffy connection is where the plug connects to the ECU, it won't make any difference. See if you can find something the same thickness as the pins (a piece cut from a feeler gauge maybe?) and try it in the plug to make sure there is tension in each socket.

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Not sure if I understand correctly.

You mean inserting a very thin piece of conductive metal in the connector, where the wire from the sensor enters the connector ?

Thanks

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Yes, I was meaning at the ECU end but you can do the same at the sensor end. Doesn't need to be conductive but if you've got something the same size and thickness as the pin on the ECU, then you will be able to feel if it is a nice tight fit or if the connector has weakened so not making good contact with the ECU pin.

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The connector at the ECU is not good with sticking probes into the connector. If the terminals inside the connector open even the slightest you will have O2 Errors. Remove the terminals one at a time and use a very small flat blade screwdriver to firm up the terminal spring. Also check the terminals are still square.