Practically Classics Forum

well i went to the garage & the guy plugged in the obd reader, & after many minutes of button pressing & fiddling with the computer & car, he said " ive never had one like that " light on, no code! so he disconnected the egr valve made a fault & cleared the problem & light is now out.... 30€ for the pleasure but the car will now pass its ct (mot)

The Renault is a bit like our Pugs .. a standard OBD reader doesn't get to all the codes .. and often what it returns is nothing like the actual issue. Even now my Sealey specific box returns odd codes when we are pretty sure it isn't what it says (brake light switch!)

I think the manufacturers were crafty when the EU made it possible for any garage to service a vehicle and not impact the warranty and told all european manufacturers to standardise on EOBD. That stuffs some older OBD2 units as the codes are slightly different. They also moved some of the electronics to separate units that are not accessible from the ECU and therefore the OBD readers.. Pug have the ECU and BSI units .. then they have two different wiring systems .. the newer Multiplex (Canbus?) and the older one. Plus airbags, ABS, etc ..

We had a problem with the EGR valve on our 1.5dCi and in the end I swapped it out. That has made the car a lot more reliable .. followed by a pair of glowplugs, and swapped out the glowplug relay. But it still goes into limp mode occasionally .. apparently due to the brake light switch!

When I had a problem with my late lamented Citroen C5 I bought a knock-off of the official Citroen device for £85 on eBay. It did all Peugeots and Citroens from 1997 onwards. May be worth investing in if you're going to stick to those marques.

Took clio for ct and it failed badly on emissions and needed 4 new tyres.. i gave it new oil and filters and a set of tyres then gave it a good thrashing and it passed.. tester was impressed with the as it had been over twice the limit.. i had the mechanic put the warning light out again and for once it registered a fault.. dodgy connection to no4 injector.. we'll see how long the light stays out this time..

Clio seems to be happy but the galaxy has got jelous of all the time ive spent with my other mistress.. i took galaxy to work the other day and noticed a very slight squeaky noise coming from the back.. after half an hour poking and prodding the usual suspects i spotted the exhaust pipe sitting a a rather jaunty angle.. it had broken off resulting in the squeak... oddly enough the engine doesn't sound any noisier than usual

For those who have been following this thread, the engine warning light has been on since 3 days after the mot.. i finally got round to getting the cam belt changed and front struts.. while he was at it he plugged in the code readers... it finally showed a fault code!!!
He couldn't find what it means though.. so does anyone know po685 means? And is it expensive???

Not that clear on google searches but seems it refers to ECM/PCM power relay

Answer on one forum is :

In the relay box in the engine bay, to the right if looking from the front, one of the small relays, bottom left or bottom right depending on which way round the box is (a bit confusing on autodata).
What fault are you having? These Clios suffer from corrosion in that relay plate due to water ingress!

I can't remember what our Clio kept throwing up (I've driven into MOT WITH the code reader connected to wipe the faults in the past!). I do now the one time is cut-out completely (used to go into limp-mode) AA diagnosed it as the "high pressure fuel pump" .. I plugged it in after getting towed home and it was something about injector relay. So swapped the latter out and still had the code! I was about to try and get a 2nd hand pump (£££s) when I read something about the glow-plugs so tested those using a multi-meter and lo-and-behold two were dead. Swapped them out and bingo! No faults!

Thanks, can you post a video of testing the glow plugs?
Ive just bought a multi meter thing and ive no idea what im doing

You just need to disconnect the connection to the plug and, with the meter on a low resistance (ohms) range, measure the resistance between the connector on the plug and the body of the plug where it screws into the cylinder head a good plug will show about one ohm, much more than that and it's duff.

Dick wrote: ↑

Thu Aug 06, 2020 7:46 am

Thanks, can you post a video of testing the glow plugs?
Ive just bought a multi meter thing and ive no idea what im doing

I would but the Clio went to the great scrap yard in the sky last year .. it dumped the contents of the gearbox (including most of the metal bits) on a stretch of road in the Lake District .. and we decided enough was enough .. now replaced with a 100hp Ford Fiesta EcoBoost with zero road tax and much better mpg than the diesel Clio!!


I found the routine via google I think on a Renault forum (maybe https://www.renaultforums.co.uk ) But as suffolkpete says it was down to measuring the resistance of the plug. They came out without too much hassle either and I picked up two new ones at a local ECP the same day.