Hi all, 

My newly acquired mk3 focus 1.6 tdci seems to have a strange starting trait first thing. 

If the cars been left overnight when you get in it and try to start it nothing happens, the ignition lights all come on but when you press the power button the car doesn't attempt to start, if you leave it with the ignition on for 2 or 3 minutes then press the start button it fires straight up and behaves normally for the rest of the day. 

I'm not sure where to start looking really, I don't think it's the battery as when the car does turn over it's fine, with no signs it's struggling. 

Anyone any ideas? 

Thanks

Chris

Check the battery voltage with a multi meter after the car has been standing idle overnight.

Agree with battery and all connections but it smacks of possible glow plug issues although I don't understand why leaving ignition on would have that specific effect unless it added some heat.
Does it crank quickly/normally as you say, and does this get worse during current cold snap?

When it starts it cranks absolutely fine, but until that point pressing the power button does nothing, the ignition lights just stay on and nothing happens, no cranking or anything. 

I'll check the battery but I'm not convinced, an agm battery is unlikely to warm up and recover voltage if it's low unlike a lithium ion can, and I had the stereo and ignition on for about 40 minutes earlier whilst waiting for someone and it fired straight up when I was ready to leave. 

Thanks

Chris

 

46 minutes ago, thomp1983 said:

but I'm not convinced, an agm battery is unlikely to warm up and recover voltage

I think he means the Glow Plugs add some heat to the engine.

It possibly won't attempt to start until the glow plugs have come on.

my car does the same

someone told me if the weather is cold then it will take just that tad longer for the engine to fire.

I'll chuck my code reader at it at some point this week and check if all the glow plugs are working or any other issues we shown. 

My mk3.5 1.5 tdci has a slight delay in starting when weather cold but only a second or so and message shows on screen adivising preignition warm up etc. 

Peter

Agree with the above, AFAIK, PCM tells glow plug module to activate plugs for longer time when it is cold (leading to a normal few seconds delay starting) but also keeps them on in various other situations (a few minutes after start for emissions and during DPF regens)?
Forscan has some parameters related to glow plug activation so worth looking at that then seeing if glow plugs have continuity then is there actually voltage and current flow to the plugs (I'm in the middle of that now!)

Ok here's a quick video of it this morning, 

So yes it started relatively quickly at 20 seconds but the bit at 10 seconds where the ignition goes off when I press the button to start isn't right, the ignition should stay on and the car start to turn over. 

I've not tested the battery yet, I've ordered a proper battery tester in the black Friday sales so just waiting on that arriving instead of just checking the voltage with a multimeter.

Thanks

Chris

We can't see what you're doing with the ignition in that video.  Are you switching ignition on first?  That's just draining the battery if so.  Press to start immediately and the starter will fire as soon as the glowplug light goes out.

Ok so I've managed to upload the whole video this time so you can see the power button.

What happened is, I got in car pushed clutch pedal and hold to the floor then press power button this just turns the ignition on but it should start the car, at 13 seconds I press the power button again and the ignition goes off, I then press the power button again and the car starts. The clutch pedal is in the whole time so the car should start. 

Thanks

Chris. 

 

Ah I see.  Yes, something odd going there.  It seems to be just switching the ignition on rather than trying to start.

First thought would be clutch switch - but isn't that because it started second time and never asked you to press the brake as well.

Second thought would be the button cycle in the BCM getting 'confused' for want of a better word.  There might be a workaround for this if you hold the start button for one or two seconds initially rather than just giving it a quick press.

I don't think this will be a battery related issue but might be proven wrong there.

I do wonder if this is possibly the corroded bcm connector issue that can occur. 

The bit that doesn't make sense is it's just the first start of the day. 

I did wonder about the clutch switch as the pedal doesn't feel right over night it feels a bit spongy but I'm replacing the whole clutch and dmf next week so any issues there should be resolved soon. 

Bit more information, last night before work I scanned the car and apart from headlight related fault codes there was nothing. 

This morning having left the car overnight I've tested the battery, the results are below, 

So the battery is fine albeit the charge is a bit low so I'll stick it on charge but I can't see that being the issue but we'll see. 

Chris 

2 hours ago, thomp1983 said:

the charge is a bit low

The charge is very low. Ford start to progressively shut things down on the car when the charge drops below 70%.

I wonder how that tool has calculated the SOC.  12.2v should be be over 50%, not 30%. 🤔

No idea how it's calculated but the tester scored well during reviews so I'll assume it's right. 

I'll be doing the clutch and flywheel this week so I'll, take it off and put it on charge for a couple of days at the same time and then retest it 

49 minutes ago, thomp1983 said:

No idea how it's calculated but the tester scored well during reviews so I'll assume it's right. 

I see that you say the battery is an AGM type which is unusual for your model, have you checked that is correct ?

When you used the tester did you have to tell it the type of battery fitted ?

The cars got stop start so an efb battery is correct, I checked the details online against what's fitted last night and they match up. 

It's a yuasa battery and doesn't look that old so should be a decent battery. 

Yes you enter the battery details into the tester before performing the test. 

4 minutes ago, thomp1983 said:

The cars got stop start so an efb battery is correct

An EFB battery is correct, but you said it had an AGM battery.

On 11/24/2025 at 6:15 PM, thomp1983 said:

I'll check the battery but I'm not convinced, an agm battery is unlikely to warm up and recover voltage if it's low unlike a lithium ion can, and I had the stereo and ignition on for about 40 minutes earlier whilst waiting for someone and it fired straight up when I was ready to leave. 

 

So interestingly after a couple of days on charge and disconnected from the car completely it's failed the battery test so I've ordered a new one should be here tomorrow. 

Let's see if thay solves the starting issue. 

 

Thank,

Chris

So I fitted a new fully charged battery this afternoon and reset the bms so tomorrow morning when I finish work we'll see if it's made a difference or if there's a greater issue to be solved. 

Thanks

Chris

Brand new battery already lost 20% health?  Can't say I've got much trust in this battery tester.

2 hours ago, TomsFocus said:

Brand new battery already lost 20% health? 

I would guess that the battery had not been charged for a full 24 hours before fitting. The big problem with all modern Smart chargers is they don't display the charging current, but instead display a charging voltage. They all have little bar graphs that give the impression that the battery is 'full' after only six or seven hours.