405 Immobiliser fault

rhw · Post by **rhw** » 05 Aug 2005, 23:36

Ive had my 1997 diesel 405 Exec 4 years with no immobiliser problem, but the battery has been out for several months. Now, when I enter the immobiliser code the green light comes on but the red one stays on too (in fact it now does this with any code!). Engine turns well (good battery), but won't start. Immobiliser does not beeep when engine turns so I assume it is recognising a code has been entered. Any help appreciated, either to correct the fault or by-pass the immobiliser!

PowerLee · Post by **PowerLee** » 06 Aug 2005, 00:10

Hi
Make sure theres no blown fuses in the fuse boxes.
Check the 3 large wiring loom connections behind the passenger side headlamp, These always give trouble because of the rubbish design, Wait untill you undo them & see the classic design cock up by Peugeot. Make sure they are making good contact & the terminals are clean.
If it has a fuel safety shut off switch then check this hasnt tripped, I know the petrol engine have this but not sure if the diesel 405s do.
You could try an auto locksmith because there are people out there who can bypass these keypads.
If all else fails then you need to get at the fuel pump stop relay, This is protected by a steel plate & can be a right swine to get off.
Get the steel security plate off, Repace the coded stop pump relay with a standard one & its goodbye keypad.

rhw · Post by **rhw** » 21 Aug 2005, 01:38

Thanks for the help PowerLee. No mention of a fuel safety shut off in either the Pug handbook or the Haynes manual. Fuses are all OK. Havn't tried really hard yet but the 3 main connectors seem well and truely connected - I'm a bit reluctant to separate these in case I introduce more bad connection probs (specially as I don't actually know if this is where the immobiliser prob lies). Maybe I'll try a friendly auto electrics specialist to get a steer on this...

PowerLee · Post by **PowerLee** » 21 Aug 2005, 21:26

Hi
The safety switch isn't in the handbook, There was an extra 4 page supplement for that, Im not even sure if the 405 diesels had it fitted, I know the 306 diesels of that vintage had it.
You will find the Haynes manual useless for your 405s electric's, Because you have an airbag its got a different wiring loom fitted, Its part 405 & part 306 / 406 & Mr Haynes doesn't cover that!
Those 3 main loom connections are a classic piece of rubbish design, Disconnect the battery ( radio code & shut the alarm down if it still works ) Twist the locking collar of one of the connections apart, undo the connector & see how rubbish they really are!
A male pin resting on top of another male pin, Thats it. Get resistance or dirt inside there over time & the pins heat up & move away from each other & then the electric's start playing up!
I think of the top of my head the immboiliser runs through the grey connector plug, But I cant be 100% sure!
Have a look & clean the pins up, Gently bend them to make contact if you see any duff ones.

flux · Post by **flux** » 28 Aug 2005, 02:11

<blockquote id="quote">quote:<hr height="1" noshade id="quote">There was an extra 4 page supplement for that<hr height="1" noshade id="quote"></blockquote id="quote">
Has anyone got a photocopy of this please?

PowerLee · Post by **PowerLee** » 28 Aug 2005, 17:30

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by flux

<blockquote id="quote">quote:<hr height="1" noshade id="quote">There was an extra 4 page supplement for that<hr height="1" noshade id="quote"></blockquote id="quote">
Has anyone got a photocopy of this please?
<hr height="1" noshade id="quote"></blockquote id="quote">
I had one about six weeks ago untill I traded the 405 in.
It was 3 pages on the newer style keypad, About how to work it, Using service mode, About the 30 minute lockout timer for 3 wrong code entries.
There was a page with about 4 lines on it about the fuel cut off switch too.

rhw · Post by **rhw** » 05 Sep 2005, 23:23

I've (at last) checked the 3 connectors behind the LH headlight. No sign of any problems (dirt, bending, corrosion etc) there, but as a precaution I bent all the pins to ensure good connection. Problem persists. No idea if there is a fuel shut off, but anyway I don't think this would not explain the immobiliser red ligfht stsying on.
Someone dis suggest I disconnect the battery, turn the ignition on, and then reconnect battery....no joy there either. Time to replacve the fuel pump stop relay as suggested by PowerLee perhaps....

PowerLee · Post by **PowerLee** » 05 Sep 2005, 23:41

Hi
I you replace the fuel pump stop relay with a standard one this will bypass the immobiliser nicely.
One problem, You have to get the steel security shielding off the fuel pump first.

fastandfurryous · Post by **fastandfurryous** » 06 Sep 2005, 00:16

Is that the point at which you introduce Mr. Grinder? I've heard that it can be the only way to get these off. I only ask, as I may have exactly this same problem in a week or two.

PowerLee · Post by **PowerLee** » 06 Sep 2005, 12:37

Hi
I think they are riveted on, It might be time for Mr Drill to do his thing.

rhw · Post by **rhw** » 10 Sep 2005, 21:09

Sucess - Hang out the Flags!
While looking at how best to get the security plate off (yes PowerLee it is riveted on) and generally moving wires etc around the injector pump I spotted a rubber square button just inside the drivers side wing, about 1/2 way back. Guess this is the fuel safety shut off (dont know how I mised it before). Gave it several good presses (didn't feel like it needed to be reset). Anyhow whether it was pressing this button or disturbing the wiring while fiddling, when I entered the code the red light went off and engine started first turn!
Many thanks for all helpful suggestions - I know more than I did!!

PowerLee · Post by **PowerLee** » 10 Sep 2005, 22:26

Hi
The fuel shut off safety switch is linked to the immboiliser keypad, If the safety switch has been tripped then the keypad wont accept a code & both lights will be on.
The 1995 petrol 405 I used to own had the safety switch mounted on the front side of the drivers side suspension top.
Also the switch had a black rubber cover over it & blended well with all the other stuff under the bonnet, The newer Pugs have a red cover & the latest multiplex Pugs dont even need this safety switch fitted, That function is now done by the BSI unit.