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P38a Immobiliser Problems


martinc

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So after first discovering the intricacies of the Range Rover's alarm system last september, (which a number of you helped me out with) I now appear to have a problem with the Engine ECM that is apparently getting worse.

When I originally had the issue with my car not accepting the EKA code, we discovered:

1) The actuator switch in the Driver's door was faulty hence the key codes were not being seen to unlock the vehicle (now fixed)

2) The alarm sounder is not working (although the lights do flash if the alarm is activated) - still not fixed.

3) After correctly entering the EKA code, the engine ECM had managed to lose the security code it shares with the BeCM, required reset with a testbook.

So it ran for a couple of months fine until the first time I'd not used the vehicle for 5-6 days and I went to start it and it would not turn over. Having previously fitted a new battery (as advised on here) I still had the original one in the garage and fearful of disconnecting the thing again and causing a complete fiasco like I had last time with codes etc I charged the spare, hooked it up to the still in situ battery, turned over absolutely fine, but would not start.

Ended up getting the AA to take it back into the local RR specialist and once again, although it had not completely died this time the ECM had managed to lose the security code. Garage recommended fitting a diesel battery to it (mines a petrol but given it appears to be suffering from the infamous mysterious battery drain issue I though this sounded wise), 15 mins later all sorted.

Until last week - only two weeks after having this corrected, it happened again. This time the battery was no-where near being dead. The guy from the garage kindly came to my house this time as I'm only up the road and sure enough the ECM had lost the security code. Code was reset on last friday.

I've used the car all weekend, went out to it this morning, and it's happened again. Turning over like a good-un but will not start and I'm willing to bet it's exactly the same thing. The chap from the garage is coming out to help me out tomorrow or Friday.

But obviously my question is, why the hell would the ECM be losing the security code like this all the time when I'm not getting the Key Code lockout messages in any way. Ideally if someone could suggest potiential causes for this, or alternatively a permanent way to disable this feature or bypass this lockout altogether because I'm getting to the stage where I now don't want to use the car, just in case I get somewhere and then the bl**dy thing decides not to start on the way back!

Any suggestion would be greatly appreciated.

Thanks

Martin

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The reason is they are two separate issues,the keycode lockout and EKA code are security/locking and the loss of code between the BECM and the engine ecu is just a security link between the two.If it keeps losing that code there are several causes.

1. Low battery voltage.

2.loom issues twixt BECM and engine ecu.

3.Engine compartment fusebox dying.

Fitting the latest RF receiver YWY500170 is a great help to any 433mhz equipped LP RR.

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The reason is they are two separate issues,the keycode lockout and EKA code are security/locking and the loss of code between the BECM and the engine ecu is just a security link between the two.If it keeps losing that code there are several causes.

1. Low battery voltage.

2.loom issues twixt BECM and engine ecu.

3.Engine compartment fusebox dying.

Fitting the latest RF receiver YWY500170 is a great help to any 433mhz equipped LP RR.

Ally

I was kind of thinking it could be a wiring problem because when I first had it recovered I got codes P1667 and P1672 from the diags an apparently this indicated not just the wrong security code, but a low voltage indicator on the security link (i.e. an earth possibly?).

Excuse my ignorance with the fusebox, but how does a fusebox "die"?

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the other problem here is also a sleep issue how old is the p38a? there was a recall done to make sure the becm acctualy went to sleep if it does not then it stay awake and drains the battery,but if the becm senses the drain it will shut off the circut which could be the engine bay fuse box which is linked to the engine ecu which could be the fault!

no have the ecu tested seperate from the car on a test rig by a good ecu tester(do you have a unipart agent in the area?they do it for a good price as well) i think you have a fuse box and a ecu problem but would be inclined to have the engine fuse box replaced first.

the alarm sounder is it a square block under the fuse box? is it pluged in in not then it could be faulty and the battery inside faulty or if it is pluged in and not working that could be the fault

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Try unplugging aerial for alarm receiver,its located behind the parcel shelf trim near drivers side rear window.This will stop the vehicle picking up any random signals and waking the becm up.You might have to put the remote very near to the rear side window to unlock it....Also strip your fusebox down and inspect it for damage as stated by other guys.Clean all earth connections as well.......

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Not sure if it will work for you but I ended up pretty much bypassing the standard alamr by fitting an after market one. Use the after market alamr to lock and secure it now so the RR one never kicks in.

It was locking up overnight and I was having to disconnect and reconnect the battery 2 or 3 times in the mornings before it would accept the code.

Had no problems since I stopped enabling it though!

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  • 9 months later...

Hi Guys

I'm now having problems with Keycode Lockout.

I had a flat battery about 9 months back and got this bloody Keycode lockout eventually found out what me code was and then entered it after several ways it worked all gr8.

Now i've had a flat battery again and battery is u/s fitted new one but cant get the EKA to work no flashing lights or anything as i seem to remember last time there was a flashing hazard ligfht when it goes in right.

Any help much appreciated.

My local LR independent garage reckon they can input the EKA with the T4 diagnostics is this true ????

CARL

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