405 Knock Sensor???

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AndyGimpy
Posts: 34
Joined: 12 Dec 2002, 18:05

405 Knock Sensor???

Post by AndyGimpy » 06 Nov 2003, 22:11

I hope someone can help here.
My father has a 94/95 405 2.0I (XU10J2) The little orange light with an engine symbol on is illuminated on the dashboard and the car seems to have a very slight lumpy tick over(cant really feel it but visible as the engine rocks) The car seems to have a power loss on driving.
The spark plugs have been changed and this has made no difference. The HT leads seem ok as when removing them you can see the engine missfire and pickup again when replaced.Just to make sure I have replaced with new HT leads and no improvement. Am I on the right track or can anyone give any suggestions.
Thanks
Andy

CANDO
Posts: 44
Joined: 27 Jul 2003, 16:18

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Post by CANDO » 11 Nov 2003, 00:52

The orange light is the Engine auto diagnostic warning indicator.
It is basically tell you that there is a fault with the Ignition/fuel injection systems.
It could be a faulty sensor or something as simple as a poor connection to a sensor.
As a first move I would disconnect each sensor plug and spray it with a contact cleaner (Maplin electronics do one for £2-£3) allowing it dry and then refit. Make sure you disconnect the battery
-ve lead first and check that you have the radio anti theft code if needed.

AndyGimpy
Posts: 34
Joined: 12 Dec 2002, 18:05

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Post by AndyGimpy » 11 Nov 2003, 16:18

Thanks Cando, I shall certainly check the connections. If all else fails its off to the dealer to get totally ripped off! This is the only problem with todays more modern cars. Even the most simple jobs of missfires cant be easily found. Bring back the good old cs101 points at least you could work on the dam cars!. Thanks again and I will let you know what the outcome is
Thanks
Andy

CANDO
Posts: 44
Joined: 27 Jul 2003, 16:18

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Post by CANDO » 12 Nov 2003, 02:35

Andy
I forgot to mention in my last post to also clean the plug & socket at the ECU.
I had the fault code read on my 406 2.1td and then replaced the sensor concerned only to find it was not at fault. After talking to I local garage I cleaned all of the contacts and (touch wood) it seems to have cleared the problem. So it pays to check the simple things first as the fault code reading cost £38
And the cost if they (Pug) checked the wiring to the ECU was £180+.
Malcolm

AndyGimpy
Posts: 34
Joined: 12 Dec 2002, 18:05

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Post by AndyGimpy » 14 Nov 2003, 19:19

Ok, Update. Fault found with coil (the car seems fine) Fitted new coil and yes it does run better, however the knock sensor (k) light is still illuminated. Is there anyway of checking the sensor at £ 49.00+vat from the dealer its an expensive gamble. The garage could not help anymore and advised going to a Peugeot dealer.

CANDO
Posts: 44
Joined: 27 Jul 2003, 16:18

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Post by CANDO » 16 Nov 2003, 02:58

Why do you think it’s the knock sensor?
My understanding is that the warning light indicates that there is a system fault but it does not tell you where the fault is. As I said in my original post it could be caused by any sensor fault. The sensors are used by the ECU to refine the overall engine performance. I believe that if the input from certain sensors (Air temperature, Crankshaft position etc) fails or is outside a tolerance range the ECU ignores that input and reverts to using a pre-programmed value. This enables the engine to still operate, abet at a lower efficiency, and illuminates the warning light. Having the fault code read would probably be the fastest way to show the area where the fault lies in but my own experience showed that it my not indicate the actual item that is faulty. I think the price of some sensors is quite small so it might be worth changing these to see if resolves the problem. Alternatively a non-pug garage or fuel injection specialist (Perhaps a mobile service) could possibly read the fault at lower cost.
Malcolm

rossd
Posts: 420
Joined: 16 Mar 2001, 21:18

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Post by rossd » 16 Nov 2003, 19:08

Slightly OT: It may look like a 'k' light, but its actually supposed to look like a transistor, representing the various electornic engine control systems. [:D]
Ross