C2 starting and fuse problem

[calle34]

Hello

I just picked up a 2006 C2 1,4 (KFV engine) with a starting problem. At first, it was blowing fuses when starting with the key but would bump start, so I figured it would be as easy as replacing the starter. When I was looking at the car to buy it, the A/C fan stopped working when I turned it up from 3 to 4. Now, the car won't even bump start and is stuck in eco mode. The starter clicks when I short the solenoid. I have charged the battery but it may be old, seller said it was new but it doesn't look new to me. The ground cable from the battery looks a little old and corroded, but I'm thinking this shouldn't cause a fuse to blow?

Does this indicate a bad ECU, starter, or both? The fuse box may have been replaced previously, it looks pretty new and doesn't match up with the fuse "map" in the owners manual.

[PaulC5]

Do you know which fuse is blowing and what it supplies ? Did you replace the starter ?

[ozvtr]

At first, it was blowing fuses when starting with the key but would bump start, so I figured it would be as easy as replacing the starter.

As PaulC5 says...which fuses? If it bump starts the problem is not your engine ECU. See below.

When I was looking at the car to buy it, the A/C fan stopped working when I turned it up from 3 to 4.

That is going to be the speed control resistor or a melted electrical connector that the resistor plugs into. That's the least of your worries right now.

Now, the car won't even bump start and is stuck in eco mode.

ECO mode will effectively shut the car down. Especially for a MK2 (I'll get to what a MK2 is in a minute). The car wont come out of eco mode until the engine RUNs. I am not surprised and I wont go into why but don't worry about it.

The starter clicks when I short the solenoid.

But the engine (starter) does not turn over?

I have charged the battery but it may be old, seller said it was new but it doesn't look new to me. The ground cable from the battery looks a little old and corroded, but I'm thinking this shouldn't cause a fuse to blow?

It wont be the cause of fuses blowing but corrosion on the battery terminals and connectors may stop the starter from running. Establish that the battery is good (don't guess, use some form of test gear) before proceeding. Also that the terminals are clean and crrosion free.

Does this indicate a bad ECU, starter, or both?

As i said above the ECU is OK. Could it be the starter? Yes, but it could also be a lot of things (like the battery). Try not to jump to conclusions. Work the problem one step at a time.

The fuse box may have been replaced previously, it looks pretty new and doesn't match up with the fuse "map" in the owners manual.

There may be a number of reasonable reasons for the BSM (the fuse box) to be replaced. I don't think that's relevant (at this point in time...maybe later).
Being a 2006 model your car is known as a MK2 (second generation) C2. The earlier MK2 owners hand books were copied virtually verbatim from the MK1 (first generation) hand book. It's wrong in many areas because of that. The layout of the fuse boxes in your hand book will be for the MK1 and useless to you...sorry. They produced a corrected version a few years later.

If I was you, I would concentrate on the battery and then on the starter. IMHO the starter construction is of poor engineering. A common problem is the planetary gearbox inside the starter implodes and locks-up the starter. Being a MK2 the BSM (fusebox) could play a part in this drama but you should worry about that later (after you have eliminated the battery and the starter as causes).

[calle34]

At first, it was blowing fuses when starting with the key but would bump start, so I figured it would be as easy as replacing the starter.

As PaulC5 says...which fuses? If it bump starts the problem is not your engine ECU. See below.

When I was looking at the car to buy it, the A/C fan stopped working when I turned it up from 3 to 4.

That is going to be the speed control resistor or a melted electrical connector that the resistor plugs into. That's the least of your worries right now.

Now, the car won't even bump start and is stuck in eco mode.

ECO mode will effectively shut the car down. Especially for a MK2 (I'll get to what a MK2 is in a minute). The car wont come out of eco mode until the engine RUNs. I am not surprised and I wont go into why but don't worry about it.

The starter clicks when I short the solenoid.

But the engine (starter) does not turn over?

I have charged the battery but it may be old, seller said it was new but it doesn't look new to me. The ground cable from the battery looks a little old and corroded, but I'm thinking this shouldn't cause a fuse to blow?

It wont be the cause of fuses blowing but corrosion on the battery terminals and connectors may stop the starter from running. Establish that the battery is good (don't guess, use some form of test gear) before proceeding. Also that the terminals are clean and crrosion free.

Does this indicate a bad ECU, starter, or both?

As i said above the ECU is OK. Could it be the starter? Yes, but it could also be a lot of things (like the battery). Try not to jump to conclusions. Work the problem one step at a time.

The fuse box may have been replaced previously, it looks pretty new and doesn't match up with the fuse "map" in the owners manual.

There may be a number of reasonable reasons for the BSM (the fuse box) to be replaced. I don't think that's relevant (at this point in time...maybe later).
Being a 2006 model your car is known as a MK2 (second generation) C2. The earlier MK2 owners hand books were copied virtually verbatim from the MK1 (first generation) hand book. It's wrong in many areas because of that. The layout of the fuse boxes in your hand book will be for the MK1 and useless to you...sorry. They produced a corrected version a few years later.

If I was you, I would concentrate on the battery and then on the starter. IMHO the starter construction is of poor engineering. A common problem is the planetary gearbox inside the starter implodes and locks-up the starter. Being a MK2 the BSM (fusebox) could play a part in this drama but you should worry about that later (after you have eliminated the battery and the starter as causes).

Thank you for a very thorough response. I'll start with the battery and then look at the starter. I found the corrected hand book you mentioned online which tells me my starter fuse is blown. The guy I bought it from had replaced the fuse (multiple times) with a 20A, the hand book calls for a 25A. The fan part just had me worried it would be some major electical issue that was all connected somehow.

What also had me worried was that the car wouldn't bump start. This was before I charged the battery however, and I later read that bump starting a car with a flat battery doesn't always work. After I charged the battery I only tried shorting the solenoid (and not bump starting for some reason). This made the starter click but did not turn the engine over. I won't get a chance to look at the car again for a few days, but yeah looking at the battery and starter (and fitting a 25A fuse) seem like logical steps Maybe it's as simple as a bad battery and a wrong fuse.


Unrelated, but the driver seat won't adjust lean angle. It folds and slides forward to let passengers in but won't adjust (the lever can go forward, but not back). Leaning back I feel like one side of the seat (one of my shoulders) isn't locked in place. Is this a common issue on these cars? I've messed around with all the levers and cables (inside the seat) I could find but nothing seems to work.

[ozvtr]

I think the fuse might be related to the pull in solenoid. It might be burnt out/short circuited. That alone could be the failure. It would stop the starter from running and blow the fuse. At this stage of the game I would bet real money that 50% of the remaining cars with TU engines have aftermarket starters in them!

As far as the seat goes, have you tried swinging the seat back all the way back and all the way forward?

[calle34]

I think the fuse might be related to the pull in solenoid. It might be burnt out/short circuited. That alone could be the failure. It would stop the starter from running and blow the fuse. At this stage of the game I would bet real money that 50% of the remaining cars with TU engines have aftermarket starters in them!

As far as the seat goes, have you tried swinging the seat back all the way back and all the way forward?

Hello again. Battery was bad, and so was the ground from the battery and the starter, so I replaced all those as well as the fuse. For a minute, the car came out of eco mode when I had replaced everything, but when I turned the key all I got was a click from inside the car. It did warn me about braking system and antipollution fault however, but those might be unrelated. No fuse was blown though. Now the car is back in eco mode after it had sat for only a minute, which I thought it only did after 30 minutes. Now when I short the starter solenoid, it cranks the engine just fine, but it still won't start. Fuel pump fuse is fine, but I cant hear the fuel pump when I turn the ignition on? Any ideas? Surely eco mode won't disable fuel.

For the seat, I have tried just about every WWE combo possible, still nothing. Maybe something is just broken

[xantia_v6]

ECO mode does not affect the engine starting, or anything safety related (e.g. lights).

[calle34]

On second thought, maybe the starter wasn't even bad, but anyhow now I know it's working. I removed the 3 big harness connectors in the BSM and found that they were soaked inwhat smelled like rubbing alcohol. After I dried them with compressed air, the car now starts when shorting the starter solenoid (and I can now hear the fuel pump inside the car like normal, but still no start on key. At least it isn't blowing fuses now, which I guess is progress!

[ozvtr]

Starter for the Mk2 C3 runs from a relay in the BSM.
The starting circuit for the Mk2 is: from ignition switch to BSI (glove box fuse box) from BSI to BSM (via the CAN BUS network) BSM to starter solenoid.
It's unlikely to be the ignition switch. Unlikely to be the connection from the ignition switch to the BSI. Unlikely to be the BSI. NOT the CAN BUS or you would have lots of lights on the dash. And it's not the starter.
Hmm that leaves the BSM. Unless there is some wiring problem between the BSM and the starter?
You seem to think the BSM has been changed before?
Unfortunately I can't think of a way to test the BSM. Either voltage appears at the output of the BSM when the key is at start or it doesn't. My bet is that it doesn't.
When the key is turned to start, there should be battery voltage at pin 5 of the yellow connector in the BSM.

[ozvtr]

At least it isn't blowing fuses now, which I guess is progress!

I hate to be a party pooper, but you are by-passing the fuse in the BSM. Now I'm NOT saying there is a problem...but don't count your chickens just yet.

[calle34]

Thanks for all your replies guys. I got the car running just minutes after posting here last, turns out I had just broken a connector for the starter as I was putting it back on. After cleaning out whatever liquid was in the BSM connectors and fixing the starter connector, the car now runs great!

I still can't figure out the seat though