Supernaut's Cars - 323i / Megane / ShiteLK

[stuboy]

2 hours ago, Supernaut said:

I suppose I should add that the Astra continues to randomly be a dickhead.

It goes into limp mode regardless of whether the intake temperature sensor is plugged in. Only if it's properly hot and I slow right down or stop, then start again.

Yeah, I still need to take the front bumper off and look for that cooling control module thingy. Perhaps tomorrow, got plenty time on my hands at the moment.

 

It does go well though, when not limping. I kind of love/hate it so just drive it everywhere utterly flat-out.

feel your pain same frustrations with the galaxy

[Split_Pin]

If it continues to press your buttons, bin it off, its only an old Astra. The E36 is far more worthy of your bandwidth.

[Supernaut]

1 hour ago, Split_Pin said:

If it continues to press your buttons, bin it off, its only an old Astra. The E36 is far more worthy of your bandwidth.

Well, yes.

That's true. However I desire / need a reasonably economical workhorse alongside the E36. Hell, I'd happily have something Clio sized again (but more reliable).

When/if I find gainful employment I can spend a couple of grand replacing the Astra (or if it goes through an MOT in May, keep it going).

Basically, I'm far from skint but there's not much cashflow replacing it, so I don't want to spend too much of it. Getting the E36 on the road is definitely accounted for though.

 

 

I have loads of spare time, plus a large farm shed that I cleared enough space in to use it as a workshop. So I'll continue to investigate the Astra purely as something to do.

[Dyslexic Viking]

6 minutes ago, Supernaut said:

So I'll continue to investigate the Astra purely as something to do.

That is also a good opportunity to learn more about troubleshooting cars and cars in general.

[Supernaut]

Commence investigation!

I'm well confused. This is the front left corner, with the wheel arch liner pulled right back so it's touching the caliper.

Where coolant control module?!

 

Edit: looking at the diagram on the previous page, it seems to be more inboard.

Cup of tea then back out to the shed.

[Supernaut]

Nope. This is a proper head scratcher.

There is absolutely nothing in the area this diagram suggests.

It's just a void.

My relay box also looks like this:

Relays 2 and 6 apparently control the fan. There are no relays 2 and 6. The empty one is supposedly for headlight washers, going by this page: https://fuse-box-diagrams.com/opel-astra-g-1998-2008-fuse-box/

 

I have also found loads of mentions of how every model with air conditioning has two fans on the radiator. This has air conditioning and one fan.

What sort of parts bin special is this?

 

 

In summary. Limp mode when properly hot and travelling very slowly/ stopped. Error code for cooling fan relay (which I can't find) and either unplugging or plugging back in the intake air temperature sensor boots it out of limp mode, depending on what state that sensor was in before it went into limp mode.

The cooling fan also works just fine if I unplug the temperature sensor on the thermostat housing and switch on the ignition.

The actual layout of the wiring in this particular car bears zero resemblance to anything I can find that refers to post 2001 Astra Gs (or even the pre 2001 models).

Huh?!

 

 

Massive regret for not just buying that E46 318i before it got crashed by the utter plank who did buy it.

[Mr Pastry]

27 minutes ago, Supernaut said:

The cooling fan also works just fine if I unplug the temperature sensor on the thermostat housing and switch on the ignition.

Doesn't this suggest that the sensor is faulty, rather than the relay?

[Supernaut]

Just now, Mr Pastry said:

Doesn't this suggest that the sensor is faulty, rather than the relay?

Dunno!

I use that method as a test on most cars. It makes the car see no temperature reading so it goes into panic mode and puts the fan on.

[Mr Pastry]

1 minute ago, Supernaut said:

Dunno!

I use that method as a test on most cars. It makes the car see no temperature reading so it goes into panic mode and puts the fan on.

Surely the fan sensor is just an on/off thermoswitch?

[Supernaut]

30 minutes ago, Mr Pastry said:

Surely the fan sensor is just an on/off thermoswitch?

On older cars (like my E36) yes.

On things like this and the Clio before it, no...?

 

What I'm saying is that I unplug that sensor when the engine is stone cold, then turn on the ignition. This puts it in a failsafe mode and it just puts the fan on in the absence of a temperature reading. The Clio did the same.

 

My E36 (and the Peugeot 205 I had in 2021) has a simple temperature switch mounted directly to the radiator.

[Mr Pastry]

13 minutes ago, Supernaut said:

On older cars (like my E36) yes.

On things like this and the Clio before it, no...?

I don't know tbh, but I would expect there is a separate sensor on the block or head to read the engine temperature.  You would surely not rely on a sensor on the radiator to do that.  Anyway if you can get the fan to come on, the relay must be working. 

[SiC]

Just catching up with this thread. From vague memory, the fan control module was only applicable for a few years and engine types. 

[SiC]

Are you android and do you have an ELM327?

The non-CAN version of this app used to do all the modules on my Astra G and get Vauxhall/Opel specific codes:

https://scanmyopel.com/

The lite version is free and will test if the interface works.

Trick will be to scan for codes when it's in limp mode and see what made it sad. Also live data will show if there is anything off in the sensors. 

A generic OBD2 reader will quite possibly not give you the full amount that a Vauxhall/Opel specific reader will give. Iirc only engine emissions related codes (e.g. Lambda/etc). 

[SiC]

Other option is to find someone with a Tech2 nearby ( @Saabnut?) and stuff a Opel card into it. That'll let you do everything a dealer can do. Non-CAN so you don't need the Candi module. 

[SiC]

This is the Autodata wiring diagram for a Z16XEP which from memory is twinport. This just shows connections to the relay (probably on another diagram) that drives the coolant fan through 3 relays (to give the different speeds). That ties up with you not seeing a coolant fan module in your car.

https://www.scannerdanner.com/media/kunena/attachments/10044/Opelxep.pdf

Our 2002 1.6 16v (non twinport) had that coolant fan module. Really vague memories (long time ago since I've owned or helped anyone with an Astra G) but I think it was ditched not much later and used the ECU to control the fans directly through relays like that diagram suggests. 

I don't think your limp mode problem is coolant fan related. 

[SiC]

On 05/03/2024 at 12:36, Supernaut said:

What I'm saying is that I unplug that sensor when the engine is stone cold, then turn on the ignition. This puts it in a failsafe mode and it just puts the fan on in the absence of a temperature reading. The Clio did the same.

Sorry I'm spamming your thread a bit but it's all coming back to memory in piecemeal chunks. 

 

Iirc the coolant fan module on ours is always powered. So disconnecting the temp sensor caused it to run in failsafe even when ignition is off. (I did it on ours as I suspect our coolant fan module was playing up). Those controlled by the ECU from memory would switch the fans off with ignition off in failsafe. 

Again, I don't think you have that module so shouldn't be an issue. 

 

Does this have the ECU bolted to the engine? I don't want to scare but these are prone to failure from the vibration and heat of the engines. Usually give random codes like cam sensor/misfire, limp mode and such. Especially when hot. ECU isn't easily cloned and condemned many to scrap (as well as rust). Easiest/cheapest way was a full ECU kit but they may be thin on the ground nowadays. 

Not saying it is definitely (still can be loads of other things - need code scanning) but just beware when spending too much on it. Especially don't parts dart it. 

 

[Split_Pin]

Apologies for the fools errand, my 2003 Z18XE had the coolant module, A/C but just one fan.

Mine did have the start of ECU failure I think as it would very occasionally hold back and throw the EML. Down the line and it was for sale with a mystery running issue and ultimately it got broken for parts.

[Stanky]

There is a free version of Tech2 called 'OpCom' available here:

https://www.instructables.com/OPCOM-V145-Setup-and-Installation/

And works with any old USB -> ODB2 cable. I used an old VAGCOM cable I had and it would talk to all the modules on my old Saab 9-3 (2004 vintage)

There is an official Opcom site where the software download lives. I'm sure it used to be free, but now seems to be £7.99 - I think the instructables link above is free? I think the hardest bit of the setup was getting USB pass-through as I was running it in a Windows 7 VM in Windows 10. 

[SiC]

I didn't know OpCom worked with the generic K Line to USB cables. I have only used it with the (knock-off) OpCom adapter. It worked pretty well TBF but ScanMyOpel on my phone was easier than lugging a laptop about. 

[Supernaut]

I have Android but no dongles (should probably get one).

The cooling fan did indeed shut off with the ignition. Well, it stayed on the first time until I fully started the engine then shut it off, and the fan stayed off.

 

I did wonder if it is the beginning of total ECU failure too... Sad, as it's otherwise a thoroughly decent bit of budget motoring.

It does have a very ECU looking box directly on top of the engine...

This little feller, next to the intake.

[SiC]

Have a feel to see if it is really hot when it plays up. Maybe even move it off the engine and put a fan on it?

I wouldn't write it off yet as it could be a whole number of things causing the failure. If you do get an ELM327, make sure you get one with the pic18f25k80 in it. Thats the original microcontroller used for a full ELM327. Sometimes they call it the ELM327 v1.5 (don't get the V2.1). The Chinese manufacturers have made a cheaper version of that which doesn't have anywhere near enough functionality to run something like ScanMyOpel. The decent ones should be still well under £20. 

I'm not sure how the ECU senses relay failure (going by that code) but if there is a signal on the relay switch side going to the ECU, it might throw up a failure on both the relay failing and the fan resistor failing when it goes open circuit. Those resistor packs rust out all the time as they're very exposed to the elements. 

 

[SiC]

E.g. this

https://www.ebay.co.uk/itm/225595864018

They have made a big effort with pictures to say it's a proper ELM327 knock-off. Rather than the crappier ELM327 cut down clone of a knock-off!

[Supernaut]

1 hour ago, SiC said:

E.g. this

https://www.ebay.co.uk/itm/225595864018

They have made a big effort with pictures to say it's a proper ELM327 knock-off. Rather than the crappier ELM327 cut down clone of a knock-off!

So am I right in assuming this sort of thing would be useful to have anyway? I.e. if I use different software it'll work with different cars?
Might just place a cheeky wee order for one just to have in my arsenal of tools.

 

I need to go out in the Astra tomorrow, so I'll try to remember to check the ECU's temperature if / when it goes into limp mode.

[SiC]

2 minutes ago, Supernaut said:

So am I right in assuming this sort of thing would be useful to have anyway? I.e. if I use different software it'll work with different cars?
Might just place a cheeky wee order for one just to have in my arsenal of tools.

 

I need to go out in the Astra tomorrow, so I'll try to remember to check the ECU's temperature if / when it goes into limp mode.

There are free ELM327 programs out there that will work with that adapter for standard OBD2 stuff. Basically act like the cheap generic code reader. So always handy to chuck one in the glovebox for any emergencies. 

Apart from that, there are other programs out there that use the ELM327 for more advanced functionality. Like Forscan for Fords, MultiECUScan for Fiat/Alfa/etc and a few others.

If you don't have one already then it's definitely worth having one in the toolkit imo. 

[Supernaut]

@RoverFolkUs

Come here into this thread please.

 

It's a 1.6 twinport, whatever engine code that is. It's shown errors for fuel trim and cooling fan relay.

[SiC]

16 minutes ago, Supernaut said:

errors for fuel trim

Too high or too low? What is the long term and short term trims at when cold and warm?

[Supernaut]

2 minutes ago, SiC said:

Too high or too low? What is the long term and short term trims at when cold and warm?

I unfortunately don't have that data available. I just managed to get a code on a cheapy reader once, that simply said fuel trim.

[SiC]

The current long and short terms when cold and hot should be available on live data with a cheapy reader.

Higher value = it's putting more fuel in than the original engine map

Lower value = it's putting less fuel in than the original engine map 

Have a skim through the other live data values and make sure they're sane. There should be a decent amount visible on a cheapy OBD2 reader. Stuff like coolant temp, intake temp (i.e. when engine is cold is it nearly ambient?), map pressure (1000mbar-ish will be ambient), MAF value (if it has one) and ideally see how the Lambda is switching (but most cheap tools are shit for reading lambda) and at what voltage. 

Listen to the fuel pump, both hot and cold. Either screwdriver on the sender or open the fuel filler with a screwdriver and listen. Should be a consistent motor whine with no grumbling. 

[SiC]

My suspicion/speculation, which may be completely wrong (remote internet diagnosis after all), is that a rouge sensor is making the fuel trims go massively out of whack. Hence my questions above about live data. Given it runs well if not in limp mode suggests that mechanically it is reasonably healthy. 

When plugging/unplugging those sensors to get out of limp mode, I suspect when it sees or looses a sensor the ECU goes "oh something has changed and we can't trust the fuel trims. So let's reset them". Live data should show that happening if that is the case. 

So something is causing the trims to drift more and more until bam, the fuel trim code is hit. That code may well be what triggers the limp mode. 

[Supernaut]

I suspect you're onto something there.

50-odd mile roundtrip this morning.

Outward bound; no limp mode.

Homeward bound; limp mode within a mile of beginning. Unplugged the intake air temperature sensor and it drove normally without even any lights on the dash! About 6 miles from home I slowed down to below 20mph for some roadworks, bam, limp mode.

Plugged in the cheapy code reader;

Cleared the code, shut down and restarted, full power restored but service light still on.

 

The ECU itself is only just above ambient temperature, not overly hot.