P38A Key code lockout

marjon · Jun 4, 2020

Thanks for the in-depth explanation Marty

J

martyuk · Jun 4, 2020

Datatek said:
One small point Marty, the BECM does not pulse the passive coil round the ignition lock, it simply applies a voltage to the oscillator built into the oil assembly.

Interesting - On my tester, where I've got an LED on the output to the ignition coil circuit, it shows it as pulsing on and off every half a second or so until the BECM receives a code from the fob - when it stops driving the output.

Knabrock · Jun 4, 2020

wammers said:
It may help if you clear the RF memory now and again.

Where are you going with this line of thought, O wise one?
I would have thought having disconnected the battery, and connecting the +ve & -ve leads for a few seconds would have cleared any transient memory?
How does one clear the RF memory?

wammers · Jun 4, 2020

Knabrock said:
Where are you going with this line of thought, O wise one?
I would have thought having disconnected the battery, and connecting the +ve & -ve leads for a few seconds would have cleared any transient memory?
How does one clear the RF memory?

With Nanocom. Go to BECM and look at top of first page RF memory and Outstation memory. Click on either as needed and choose clear memory.

Datatek · Jun 4, 2020

martyuk said:
Interesting - On my tester, where I've got an LED on the output to the ignition coil circuit, it shows it as pulsing on and off every half a second or so until the BECM receives a code from the fob - when it stops driving the output.

I have only scoped the oscillator on the bench, never bothered to look at the BECM output, but on/off at half second intervals makes sense as the oscillator only needs to be on or a very short time.

Knabrock · Jun 4, 2020

wammers said:
With Nanocom. Go to BECM and look at top of first page RF memory and Outstation memory. Click on either as needed and choose clear memory.

Just plugged in the Nanocom, to get to RF fault page which displayed sole message
"The BECM has received a valid radio code", Cleared Memory gave response "The key fob RF receivers status memory has been reset", after which radio code message reappeared.

Outstation faults displayed 2 messages (centre console and left hand seat), Cleared Outstation memory, turned on ign for 5 seconds as advised, reread Outstation faults "Communications have been detected on all outstations"

I then enabled the EKA,
Tried key fob - nothing
Tried key lock whilst pressing fob lock, key unlock whilst pressing fob unlock, fob lock/unlock - nothing
Tried EKA sequence, pressing fob whilst key in ign pos 0,1,2,3 - Engine started but no response to Fob.

I've disabled the EKA again, and will await Fob repair kit, to investigate if I can get Fob access working, just out of interest. I'm happy enough that truck is running again with keyed access.

wammers · Jun 4, 2020

Knabrock said:
Just plugged in the Nanocom, to get to RF fault page which displayed sole message
"The BECM has received a valid radio code", Cleared Memory gave response "The key fob RF receivers status memory has been reset", after which radio code message reappeared.

Outstation faults displayed 2 messages (centre console and left hand seat), Cleared Outstation memory, turned on ign for 5 seconds as advised, reread Outstation faults "Communications have been detected on all outstations"

I then enabled the EKA,
Tried key fob - nothing
Tried key lock whilst pressing fob lock, key unlock whilst pressing fob unlock, fob lock/unlock - nothing
Tried EKA sequence, pressing fob whilst key in ign pos 0,1,2,3 - Engine started but no response to Fob.

I've disabled the EKA again, and will await Fob repair kit, to investigate if I can get Fob access working, just out of interest. I'm happy enough that truck is running again with keyed access.

The fob cannot be synced unless the EKA code has been correctly applied and accepted.

Knabrock · Jun 4, 2020

Ha! we can go round that loop indefinitely!
What was the intended purpose of the RF memory clear?

wammers · Jun 4, 2020

Knabrock said:
Ha! we can go round that loop indefinitely!
What was the intended purpose of the RF memory clear?

Full memories can cause problems. Go round as many loops as you want to, but key fob CANNOT be synced until EKA code has been accepted.

Datatek · Jun 4, 2020

wammers said:
The fob cannot be synced unless the EKA code has been correctly applied and accepted.

Unless the EKA code is turned off

wammers · Jun 4, 2020

Datatek said:
Unless the EKA code is turned off

You can turn the EKA code off after syncing fob but you cannot sync a fob with EKA required.

Datatek · Jun 4, 2020

wammers said:
You can turn the EKA code off after syncing fob but you cannot sync a fob with EKA required.

Done it twice

Edit: Wrote that badly, I have done it on 2 P38's with EKA turned off.

wammers · Jun 5, 2020

Datatek said:
Done it twice

Not when the vehicle is in an alarmed state you haven't. There are people who do not have MSV2 or Nanocom.

Datatek · Jun 5, 2020

wammers said:
Not when the vehicle is in an alarmed state you haven't. There are people who do not have MSV2 or Nanocom.

Who mention an Alarmed State?
The FOB can be re-synced with EKA turned off.
If the BECM is in an Alarmed state even a Nanocom will not help you.

wammers · Jun 5, 2020

Datatek said:
Who mention an Alarmed State?
The FOB can be re-synced with EKA turned off.
If the BECM is in an Alarmed state even a Nanocom will not help you.

I did in an earlier post. Nobody mentioned BECM alarmed state. Do you just argue for arguments sake? You CANNOT sync a fob with ANY alarm message showing.

wammers · Jun 5, 2020

Datatek said:
Who mention an Alarmed State?
The FOB can be re-synced with EKA turned off.
If the BECM is in an Alarmed state even a Nanocom will not help you.

It can if the Nanocom EKA input is accepted. But not always by any means.

Datatek · Jun 5, 2020

wammers said:
I did in an earlier post. Nobody mentioned BECM alarmed state. Do you just argue for arguments sake? You CANNOT sync a fob with ANY alarm message showing.

I'm not arguing you are talking about a different situation. If the FOB loses sync with the BECM it can be re synced with the EKA code turned off without the need for Nanocom or Faultmate.
Since turning off EKA and Immobiliser I have never had ANY alarm message of any sort.
Marty provided a good explanation.

wammers · Jun 5, 2020

Datatek said:
I'm not arguing you are talking about a different situation. If the FOB loses sync with the BECM it can be re synced with the EKA code turned off without the need for Nanocom or Faultmate.
Since turning off EKA and Immobiliser I have never had ANY alarm message of any sort.
Marty provided a good explanation.

How do you turn the need for the EKA code off without diag?

Datatek · Jun 5, 2020

wammers said:
How do you turn the need for the EKA code off without diag?

You don't, as you very well know.

wammers · Jun 5, 2020

Datatek said:
You don't, as you very well know.

I do as it was i who first suggested disabling EKA and immobiliser until a members door lock problems could be sorted.

P38A Key code lockout

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