Speedo fault.

[Glynn]

Hello there, Got a problem with my 2001 406 2.0 hdi 110 Executive. The Speedo would sometimes work and sometimes not work. I plugged my scan tool in the car and took it for a run and the speed sensor wasn't registering any speed whatsoever on the scan tool so that led me to believe it was a fault with the speed sensor. So I ordered one off of ebay. I fitted the new speed sensor and again the same fault appeared with the speedo working on and off but this after about 30 miles it stopped working completely. So I plugged my scan tool back in and went for a run and the speed sensor was still not registering anything so ordered another speed sensor, this time a good quality one from the dealer. I plugged it in and it still did not work...... So I decided it would possibly be something to do with the earths so I cleaned all the earth's up and and all the connectors up in the engine bay and took it for a run and still nothing. So now I am at a loss to know what the hell it could be causing it not to work. So If anyone has any ideas leave a message . Cheers Glynn.

[Doggy]

Being a 2001, your car could have semi or full-mux electrics. This makes a difference - the earlier cars use a speed sensor mounted in the diff housing to measure road speed, its output is connected to both the engine ecu and the BSI, (body systems interface), that sends the data to the instrument cluster.

On later cars, road speed is measured by the ABS control module, using the two front wheel ABS sensors. The resulting digital speed data is communicated to both the engine ecu and BSI via can bus, then from BSI to the instrument cluster.

Sorry if that all sounds like fluent geek, but it will make sense as you get into it.....

[PeterN]

If you have been able to change your sensor sounds like the earlier type, its mounted on the diff housing just above the o/s drive shaft entry point. If this is yours it could be the connector that's at fault. I know its not very easy to get at but have a close look at it if you can and make sure the wires are secure and not broken internally. If you can get to the outside of the pins on the plug try bending them in a bit so they make better contact with the socket on the sensor.

If its all OK down there its there is probably another poor connection in the circuit, the XMs used to suffer with dry joints actually on the instrument panel.

Peter

[Doggy]

To clarify, both versions have the diff mounted speed sensor, but on the newer cars, it's only used for satnav, auto door locking, fast idle and wiper control, (AFAIK).

[Glynn]

Being a 2001, your car could have semi or full-mux electrics. This makes a difference - the earlier cars use a speed sensor mounted in the diff housing to measure road speed, its output is connected to both the engine ecu and the BSI, (body systems interface), that sends the data to the instrument cluster.

On later cars, road speed is measured by the ABS control module, using the two front wheel ABS sensors. The resulting digital speed data is communicated to both the engine ecu and BSI via can bus, then from BSI to the instrument cluster.

Sorry if that all sounds like fluent geek, but it will make sense as you get into it.....

Im not sure if mines the earlier type electrics or the later. Ive had alook on the log book and the car was registered 24th march 2001 so Im guessing would have been manufactured in late 2000 sometime. So would that put it in the range of the earlier type electrics do you know?

[Glynn]

If you have been able to change your sensor sounds like the earlier type, its mounted on the diff housing just above the o/s drive shaft entry point. If this is yours it could be the connector that's at fault. I know its not very easy to get at but have a close look at it if you can and make sure the wires are secure and not broken internally. If you can get to the outside of the pins on the plug try bending them in a bit so they make better contact with the socket on the sensor.

If its all OK down there its there is probably another poor connection in the circuit, the XMs used to suffer with dry joints actually on the instrument panel.

Peter

Yeah, checked the connector and cleaned it out with some electrical contact spray and checked for anyloose wires in the back of the plug or chaffing and everything looked ok from what I could see.

[jonsowman]

What's your build code (on the door sticker)? That might help us narrow things down a bit.

9001 or later is full mux, 9000 or earlier is semi mux

[Glynn]

What's your build code (on the door sticker)? That might help us narrow things down a bit.

9001 or later is full mux, 9000 or earlier is semi mux

The only stickers I could see was the one with the tyre pressures on and below that on the same sticker was 3 sets of numbers and letters. Here they are:-

0885889
20737
ekzd
7340

[jonsowman]

8858 is the build code so yours is semi-mux So the speed sensor on the box is indeed used to drive the dash gauge.

[Glynn]

8858 is the build code so yours is semi-mux So the speed sensor on the box is indeed used to drive the dash gauge.

Ok thanks mate cheers.

[steve_earwig]

Hi Glynn

To clarify, both versions have the diff mounted speed sensor, but on the newer cars, it's only used for satnav, auto door locking, fast idle and wiper control, (AFAIK).

Really? I didn't think they brought that s**t in until the 407 Looks like I've been hitting the wrong thing when Sedre asks if it has captur filaire vitesse abs bv whatever it's in forrin innit.

Anyone else with Sedre wondering why it shows 6 different versions of the speed sensor for different engines, yet they all appear identical? I checked Service Box, there can be only one

The speedo on a semi-mux is still run by the BSI

I guess I'm a bit sceptical whether a generic code reader could diagnose this one properly, does a semi- still do the low speed/intermittent wiper thing?

If it is right, I'm thinking either a wire is broken between the sensor and the BSI or the BSI has an "issue" Worth checking for under carpet dampness?

[markw]

Anyone else with Sedre wondering why it shows 6 different versions of the speed sensor for different engines

If we're looking at the same diagram, that's not the gearbox sensor, but the crank sensor.
It's showing the same sensor six times, (although one appears to have a shielded 3 wire connection...?) and the different pin connections to the various engine ecus.

[steve_earwig]

Que? Oh goddam it, how did I manage to bring that up?
It still heads off to the BSI tho

[Glynn]

I've booked it into be looked at by a guy in sheffield called steve plain who's a peugeot specialist so hopefully he'll be able too figure out whats up with it. I've done everything I can with it. So will leave it too him and I will let everyone know what was causing the problem. cheers for input.

[Glynn]

Solved. The first speed sensor I bought off of ebay I thought was not working actually had the wrong number of teeth on the driver gear that came with it, and so I bought a another one and swapped the gear over thats why i still had same problem. So the guy who found the fault ordered me a proper speed sensor gear and fitted it for me and everythings working fine now. Im not buying anymore ebay crap from now on.