207cc Crank but no start.

[Colin2206]

[Colin2206]

psf1 = Engine F/Box
1370 = Engine Mangement single Relay
1320 = Ecu

[wheeler]

You sure this diagram is correct? would be unusual to have an external injection relay on this age of car never mind a 5 pin one? Even the older ones pre BSM were 15 pin 'double' relays.
Where does the diagram show 1370 being located?

[wurlycorner]

I can't comment on that being the right circuit or not, but either way that's only a partial circuit (very limited function) What is it labelled as being the circuit for?

Just dropping back on some of your earlier posts:

Checked the crankshaft sensor wiring, all ok but fitted a new sensor anyway.

So you changed the crank position sensor even though weren't sure if the original one was faulty. I can understand the temptation to do that, but a) did it test open circuit or give sensible resistance values when you check it directly with the multi-meter, b) does it have power supplied to it on one side (might only be during crank) c) was it replaced with an OEM one? Cheap aftermarket sensors often cause more problems than they fix, so if you can't confirm the original sensor was faulty and it was an aftermarket non OEM sensor that you fitted, then I'd put the original back if I were you, at this stage [and see the end of my post for what I really advise here in order to confirm if it's ok or not]

On advice of electrician checked the supply feed to the ECU. Nothing but..

So with reference to the circuit on the previous page, what have you confirmed at the ECU? No +12v on pin..?
And just to be clear, from what you've said, I assume this was checked during ignition on only (not during crank), yes?

Did you check all other pins at the ECU (in case that circuit schematic is wrong) or just check in accordance with that circuit schematic alone?

. Also I am checking on the plug and battery negative i.e. the plug is not on the ECU. I don't think that will make a difference but again if you know different please let me know.

If you have the ECU unplugged, then on the basis of that circuit schematic, the ground to pin 2 on the single engine relay will be lost, which means that relay won't close, which means there will be no output from the single relay to the ECU (which means you wouldn't ever get +12v on pin 2 at the ECU). So no, I'm afraid you do need to test for power/ground at the ECU with it plugged in (or provide a temporary direct ground to pin 5 on the ECU plug).

Ref whether you should have power at pin 2 with just ignition on, impossible to say from that circuit because it is only a partial circuit - Where does E120C go? Without a supply from that connector onto Pin 1 of the single relay, you would get no output from the relay. And without the rest of the circuit, we don't know what turns on the feed from connector E120C/in what state it would be live. We also don't know what pin 8 at the ECU is meant to provide - is it meant to be +12v or ground, or a signal etc?

At risk of repeating myself here, while.itnwas absolutely right to first of all chrck of you had fuel/spark and it's worth trying to check the basics about is there power/ground to the ECU etc. It honestly is worth getting a lexia/diagbox or some other diagnostic tool on this, to confirm some of the wider functional basics. It will save you so much time and possible parts changing/trying to locate components in hope.
It would tell you not just if there are any DTC's stored (which might give direction) but also e.g.: is there communication with the engine ECU?; does the engine ECU see rpm when the engine is cranking?: can you fire the injectors manually from the ECU as a functional test etc.

[Colin2206]

Sorry, I've not been clear.
Wheeler:
The Relay is identfied as a seperate item on the electrical diagrams but as you pointed out, in reality it is integral to the "Fusebox". I've not been able to find a location on any Forum, website or drawing. The local Peugeot dealer was also stumpted. I've checked the wiring harness between the Fusebox and the ECU, there is only harness, no other items. The diagrams are from the Servicebox. What I have shown is a Snip from the very large schematic. It is accurate for other items I've been checking (coil, injectors, etc.)

wurlycorner
Crankshaft Senor wiring all ok, supply and return. The space is so tight I couldn't test it insitu, so for £20 a simple change out is the way to go. I agree because an item is new does not guarantee it is in good condition.
So with reference to the circuit on the previous page, what have you confirmed at the ECU? No +12v on pin..?
And just to be clear, from what you've said, I assume this was checked during ignition on only (not during crank), yes? Correct. Checked against the Schematic only. Unless some indication otherwise, I'll assume information in ServicBox is correct.

If you have the ECU unplugged, then on the basis of that circuit schematic, the ground to pin 2 on the single engine relay will be lost, which means that relay won't close, which means there will be no output from the single relay to the ECU (which means you wouldn't ever get +12v on pin 2 at the ECU). So no, I'm afraid you do need to test for power/ground at the ECU with it plugged in (or provide a temporary direct ground to pin 5 on the ECU plug). I think I understand the point your making and I will retest for this tomorrow.

Your other points about getting other test equipment. The car 15 years old and border line worth getting professional help to repair. Other than my own time I've only spent £20 for sensor and £50 for refurbished Fusebox (due in the next couple of days). If that doesn't work, I need to consider what to do. The car would need to be towed to a repairer, cost of repair etc. for a car 15 years old. I'm retired and happy to do simple reairs and oil changes, but not chasing a fault for days on end. Maybe time for a car that can give me 5 years reliable running.

[wheeler]

If the wire number & pin location on the ECU plug match the diagram i would give that wire at the ECU connector a (fused) 12v feed & see if the engine starts.

[wurlycorner]

If the wire number & pin location on the ECU plug match the diagram i would give that wire at the ECU connector a (fused) 12v feed & see if the engine starts.

Yep, also worth a try, if testing the normal supply when all plugged in, shows no feed.
Just worth noting that sometimes putting a slaved in permanent feed can cause Engine management ECU's to get upset though (if it's meant to be part of an actively latched supply and the input doesn't work as expected, the ECU's go into fault mode etc.)

Colin, re: diagnostic test equipment, I wasn't suggesting you need to send the car off to someone for testing or to spend a lot of money.
If you look here there might be a member local to you that is willing to drop by with their lexia/planet/diagbox to help.

[Colin2206]

I've been putting this back together, cleaning, etc. I've discovered the dedicated earth return on the Engine fusebox has a resistence of 500 ohms, which seems far too high. The cable goes into a harness and disappears behind the engine. So I'm thinking of putting a return direct to the battery terminal. Any thoughts on this?

[wurlycorner]

I've discovered the dedicated earth return on the Engine fusebox has a resistence of 500 ohms, which seems far too high.

That's way too high, yes. I assume that's measured from the earth terminal at the fuse box, to the battery negative terminal/a good body ground somewhere else?
You could also measure the voltage drop between the earth terminal at the fuse box and the battery negative terminal to confirm if that's causing an issue. Should be millivolts, nothing more. Ideally do that while cranking as well, so the system is under maximum load.

The cable goes into a harness and disappears behind the engine. So I'm thinking of putting a return direct to the battery terminal. Any thoughts on this?

This would be a way round that problem yes - assuming you can't see what's wrong with the existing earth and rectify that.

[wheeler]

So I'm thinking of putting a return direct to the battery terminal. Any thoughts on this?

Absolutely yes however it would be ideal to find the reason for this incase it is more future problems.
Id at least try to find the earth point it connects to & remove & clean it.

[Colin2206]

Well, I've had quite a day, not the one I was expecting.
There has been "progess". After putting everything back together and a near fire putting an additional earth in, the bad earth from the fusebox now has <1 ohm.
With only the c/shaft sensor replaced, I cranked the engine over and it ran...for a good 1 1/2 seconds and I got a fault code, the first. P0339 "circuit intermittent."
I put the original sensor back in and got the same fault.
Now I had checked the wiring, supply and return and earth at the start, but I'll redo that tomorrow. The position under the car is restricted, so possibly get it up a bit higher first. Some youtubes say there may be a "relearn procedure" but I would think the engine needs to run first.

[Colin2206]

Well, checked old and new crankshaft sensors. Both generated a signal that went from -5 to +5v.
Still no start, occasional cough and less than 2sec run. This confuses me. Also fault code won't reset, just remains on the reader. In the past when I deleted a code, the code went away (although it could re-appear on the next start).
Anyway, going to look for a replacement over the weekend.

[wurlycorner]

I know the code says it's for a crank sensor, but does that engine also have a cam sensor? If so, check that as well (it could be a correlation issue and the ECU is for triggering the wrong code in its analysis).

[Colin2206]

It has a double cam engine, so I'll look at them; not sure how I can reset/calibrate them, maybe just unplug them and crank.
I think it may be the plug at the c/shaft sensor, the wires are twisted and pulled tight. Not had any luck identifying a replacement yet.

[moizeau]

If your crank sensor is the 2 pin induction type they can be tested. A mate had one go on his 206cc 1.6 petrol. Put a multimeter across the pins on the sensor. It should give a small resistance figure, 0.5 ohm, then set it to dc volts (lowest setting) and move a ferrous object towards the sensor, it should give around 0.5v from memory. The knackered one showed open circuit and 0.00001v. You could compare the 2.