Error Codes and underlying fault

[nobbyc]

Hope I'm posting in the right place.
Car is Clio 1.5 DCi 2002
Engine management light came on and the engine died.
Fiddled around with wiring and checked various connectors for a while and engine started with no warning lights lit.
Drove around for 100miles with no problem.
Swopped our cars back and off she went in the Clio.
5 miles later the engine dies, with the STOP and engine mangt lights lit.
Towed to the local garage (was going in for new wheel bearings anyway).
Professional tester plugged in and came up with some odd output codes that grage had not come across.
04111,
04134,
04203.
Not wanting to spend more than the car's value, I called a halt to the investigation, but thankfully after the mechanic had jiggled the steering column. jiggling appeared to correct the fault and the car started fine.

Hoping to gain wisdom on two things:

1. does anyone know the meaning of these fault codes? I'm guessing that the 2002 diesel Clio is not EOBD compliant and ouputs according to its own rules whatever they are. (Which makes me less keen to buy the cables and scanning software for my laptop for home investigation but I'm really keen to be convinced otherwise by any replies.)
2. Please can anyone suggest where the true fault might lie. I was originally thinking the accelerator potentiometer, or the wiring around the steering column/pedal area, or the wiring to the ignition switch.

Sorry for the long post but wanted to give as much info as possible.
P.S. the engine/gearbox/turbo/fuel pump etc. is a replacement, from a 2006 1.5 DCi Kangoo (rear ended after 4000 miles) which dropped into the Clio beautifully (engine now covered 25000).

Obliged for any advice given.
Ian

	Turbo Turbo A turbocharger is an exhaust gas-driven compressor used to increase the power output of an internal-combustion engine by compressing air that is entering the engine thus increasing the amount of available oxygen. A key advantage of turbochargers is that they offer a considerable increase in engine power with only a slight increase in weight.

[madnoel10]

What type of system key is fitted - is it the keycard type or ordinary blade key type?

Sorry I haven't a clue what the codes mean but as you have already guessed not all code readers can gain full access to the Renault ECU as it uses a different protocol than most other European manufacturers.

For what's worth it could be you have a steering lock problem (the electronic bit) as the ECU will not let the engine to start if it thinks the steering is locked. It could be something as simple as a loose connection or broken wire.

	ECU Electronic Control Unit In automotive electronics, an electronic control unit (ECU) is an embedded system that controls one or more of the electrical subsystems in a vehicle. Some modern cars have up to 70 ECUs.

[nobbyc]

Many thanks for your speedy and encouraging reply Noel.
The key is a straightforward blade type with just a lock/unlock button on the fob.

It would be good to know what protocol Renault used for the Clio diesel in 2002, with view to finding a scanner that inculdes it. Though diesels only had to conform to EOBD in 2004, I was hoping the Clio had the ISO 9141-2 standard, but the garage's scanner would have coped with that I think. I'll have a close look at the socket for pinouts to find out more.

Thanks for the tip. I'll be dismantling down to the steering lock as soon as I get home on the bus - yes she's got my car

Edit following madnoel10's reply below: I'm a little disappointed with Renault lack of transparency & not conforming to EOBD modes and PIDs - it makes it nigh impossible for example to confidently replace malfunctioning engine management sensors without resorting to a very costly visit to a Renault dealer

Thanks again
Ian

[madnoel10]

Renault have closely gaurded their protocol similar to some Toyotas and as far as I know there is no one after-market reader that can access the complete system on its own. When I mean complete system that includes the TPMS where fitted and also the ABS system. It may be possible to find readers that can do each of these aspects but as yet I haven't heard of any than can access some of the onboard UCH controlled circuits but maybe some other members may know differently.

	UCH UCH The UCH (Unite Centrale Habitacle) is an electronic control module that is fitted to many late model Renaults (early 2000's onwards.) It is responsible for controlling many of the non-engine related functions of the car, such as central locking, electric windows, and even some of the lights (e.g. indicators.) A brand new UCH is supplied with a blank memory. This must be coded (using the Renault Clip computer) to match the serial number of the ECU and key/card before it will work with the car. The memory can only be written once, so a used UCH cannot be taken from a donor vehicle to be used in another unless the ECU and keyfobs/cards are also transferred.

[nobbyc]

I've checked all around the steering column and ignition switch for problems but all here seems fine.

The car has run well for 20 miles but since no fault has been identified I expect the ECU light and Engine Management light to come on again and stop the car some time soon. I've one new observation and one suggestion as to a possible cause.

With the car idling, I've observed the flow of diesel from the pump to the filter. It's the line from the pump that has the thin pipe attached that returns diesel from the 4 injectors. Every 3 to 4 seconds the diesel flowing towards the filter has a mass of small air bubbles in it. I'm trying to figure out if this is significant and where this air originates. No air is being fed into the pump from the filter, so the only other source of bubbles is air being drawn into the return pipes via a dodgy seal at one of the many connecions leading from the 4 injectors. How should I test/cure this and do you think these bubble might cause the ECU to stop the car?

Someone has suggested that the TDC sensor could be failing once the engine has reached a higher temperature. Is it worth throwing 30 quid at renault for a new TDC to remove this possible cause?

All thoughts much appreciated
-ian

	ECU Electronic Control Unit In automotive electronics, an electronic control unit (ECU) is an embedded system that controls one or more of the electrical subsystems in a vehicle. Some modern cars have up to 70 ECUs.

	TDC TDC In a piston engine, top dead centre (TDC) is used to determine the position of a piston in which it is further from the crankshaft. This is used to determine when to generate a spark. Many Renault models appear to experience problems with the TDC sensor, but it is a simple and inexpensive part to replace.