406 ST D9 query

[tomb]

Just added a manual 2001 406 sedan to the pug fleet, one owner low klms, a few things to fix up but a nice drive, so quiet and solid on the road.

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The engine fault light comes on, not all the time according to the previous owner, the anti pollution fault comes up on the centre display when the engine light is on, apologies if this has been covered before on AF but is it something that needs to be looked at?

[SLC206]

These are both fairly generic lights that could mean any number of things.

You would really need someone to plug it into a code reader to gain some more information.

[pugnut1]

It's possible that one of the issues could be the oxy sensor, but it would be best to plug in an analyzer/code reader first

[tomb]

Thanks, scan done, as often the case somewhat inconclusive, came up with coil, lifters and injectors as possible faults.

No trouble starting, runs superbly, getting well over 900klm on a tank highway trips, so coils and injectors seem unlikely, no gear stick shake on initial start up. Lifters maybe but I doubt the previous owner has been using the wrong grade of oil, fuel economy certainly indicates he wasn't.

My money is on a bad censor probably associated with the exhaust.

The [Addo's favourite Melb pug] mechanic did give me the heads up on the water in the spare wheel well and a strange fibration at cruising speeds, which I hadn't noticed but the car does have on occasions. He's not a rap for penrite oils on euro 4 engines which suprised me, the last oil change in country SA was penrite, but the previousowner had quite a few done at Regans. Maybe an oil flush and some Elf oil will be all the lifters need. Will get a few more Klm on it and he can do the 140,000 service.

Thanks to AF I had read some good things about the petrol 406, and although getting on, they are a very nice car, as good as the Audi A4 of the same era that we have, more comfortable, more room, cruise control and auto wipers that the Audi doesn't have. Easier to get in and out of and I prefer the higher driving position.

[SLC206]

Thanks, scan done, as often the case somewhat inconclusive, came up with coil, lifters and injectors as possible faults.

What's the engine fault code for lifters?

[tomb]

What's the engine fault code for lifters?

Sorry, came up with faults that he interpreted as coil or injectors or lifters.

[Peter C]

I've recently had airbag warning lights come up (and a speedo that intermittently dropped down to zero) which have been resolved by disconnecting and reconnecting the electrical connectors a few times with a bit of WD40 at the same time. The connectors, at least the ones I've come across so far, don't seem to be of a great quality.

Although your fault lights could be completely unrelated to dodgy electrical connections I'd check this side of thing out first.

[timreverb]

I've recently had airbag warning lights come up (and a speedo that intermittently dropped down to zero) which have been resolved by disconnecting and reconnecting the electrical connectors a few times with a bit of WD40 at the same time. The connectors, at least the ones I've come across so far, don't seem to be of a great quality.

Although your fault lights could be completely unrelated to dodgy electrical connections I'd check this side of thing out first.

I'm having the speedo to zero problems too on my 406 D9. Any particular tips on which connectors I should be targeting? Cheers.

[Peter C]

Cleaning the contacts may or may not solve the problem but it's cheap to try.

On a D9 it's the one box on the firewall behind the glovebox. In my case, doing this seemed to solve the problem.

D8s and D9s are similar but there are differences. This box is larger than either of the D8s two boxes and I could only find this one box. My assumption was that it replaced the two boxes of the D8. My speedo seemed to right itself after I cleaned that connector but it could've been a co-incidence.

[hypermiler]

Speed sensor on the gearbox is a common fault that causes the speedo dropout, just needs a competent auto electrician to replace it. Tach dropping out as well at the same time is the connectors to the dash unit.

[timreverb]

Speed sensor on the gearbox is a common fault that causes the speedo dropout, just needs a competent auto electrician to replace it. Tach dropping out as well at the same time is the connectors to the dash unit.

Thanks - the tach doesn't drop out, only the speedo. However the gearbox sender was ordered by a mechanic who went to fit it only to find a blanking plate, so speed is being sent from somewhere else.

I'll try cleaning the contacts on the box on firewall behind glovebox first - thanks all.