Car cranks but no start

[sol_j]

About a week ago, my car started having an issue where it would crank but not start. Electrics came on, but I noticed I couldn’t hear the fuel pump priming anymore (I think I first noticed that a week or two before but didn’t think much of it).


Called out my breakdown cover, and after checking it over, they reckoned it was the relays under the steering wheel – rusted out. I ordered a new fuel pump relay (409), a 100 relay, and a used 377 one as replacements.

That same day, once the car started, I drove it straight to the local garage, but they told me I couldn’t leave it there as they had no space, so I took it back home. It did cut out on the way, but I just about got it started again.

I fitted the new relays yesterday and it started fine – no issues. But this morning, less than 24 hours later, it wouldn’t start again. First time I’ve noticed the ABS light come on with the car as well, if I remember right.

I’ll probably get breakdown out again, but has anyone got any ideas what else it could be? Do you reckon it might be the fuel pump itself or maybe the crank position sensor?

 

[Alexis27]

Any fault codes?

 

[sol_j]

Any fault codes?

I got this code when I scanned it last time (last Thursday.) I haven’t scanned it yet.
“1 Fault Found:
01314 - Engine Control Module
49-00 - No Communications”

what do you think?

I got it under a few modules, as in the screenshots:

 

[sol_j]

Update: idk why I didn’t put two and together but after the recovery guy came, we realised the ecu is dead as the engine light does not come on so obviously stuff like the fuel pump doesn’t prime. Is this a common issue with these to die? Is it worth getting an immo off one instead to save headache and just work? Also is it easy to remove from the car? Under the scuttle panel right?

 

[Battoussai]

Ahhh that is harsh! ECU dying is a PITA.
After some reading I found out you have to recode the immobilizer so your car keys can start the car.
And yes, the ECU is under the scuttle. Check this video: ECU swap

Are you going to buy a used ECU? Must be the EXACT same serial number.

 

[sol_j]

Ahhh that is harsh! ECU dying is a PITA.
After some reading I found out you have to recode the immobilizer so your car keys can start the car.
And yes, the ECU is under the scuttle. Check this video: ECU swap

Are you going to buy a used ECU? Must be the EXACT same serial number.

I bought an immo off one after getting the right part number from AUTODOC lol. Cba and just want it to work. Is this a common problem? How would this happen? Just age? The one I needed 06A 906 032 HN

 

[Battoussai]

I bought an immo off one after getting the right part number from AUTODOC lol. Cba and just want it to work. Is this a common problem? How would this happen? Just age? The one I needed 06A 906 032 HN

Usually is water ingress leading to rust some conections. I read could also be the ground point that is near it. After you get it out, check for rust or seized connector and try it again before buying new one.

 

[MoToJoJo]

From the factory the cars had a plastic cover over the ECU, most cars lose this over time and if you're unlucky, rain gets in and kills the ECU.

 

[sol_j]

From the factory the cars had a plastic cover over the ECU, most cars lose this over time and if you're unlucky, rain gets in and kills the ECU.

Nice one. Any idea on the oem number?

 

[sol_j]

From the factory the cars had a plastic cover over the ECU, most cars lose this over time and if you're unlucky, rain gets in and kills the ECU.

Update: it didn’t work with the new ecu. Same thing with no engine light etc.

 

[sol_j]

These are dumbed down list of symptoms I got if anyone could help:

• Car cranks (engine turns over) but doesn’t start
• No fuel pump sound when you turn the key
• No engine management light on the dash
• Nothing shows up when plugged into an OBD scanner
• Tried a different ECU – same result
• Fuses all checked and seem fine
• Relays have been replaced with new ones
• Some modules wouldn’t scan a few weeks ago

 

[sol_j]

Update: it didn’t work with the new ecu. Same thing with no engine light etc.

This is the photo of the ecu in my car. The connections looked fine tbh etc everything was plugged in correctly/ not loose

 

[Battoussai]

When I change the fuel filter on mine, It takes around 10 cranking attempts before it starts - because it is filling the canister with fuel. Now I use VCDS to perform a 30 seconds pump test that fills the filter enclosure.

If you don't hear the fuel pump working maybe it is lack of fuel. That would explain no lights, no codes, and no starting.

 

[sol_j]

When I change the fuel filter on mine, It takes around 10 cranking attempts before it starts - because it is filling the canister with fuel. Now I use VCDS to perform a 30 seconds pump test that fills the filter enclosure.

If you don't hear the fuel pump working maybe it is lack of fuel. That would explain no lights, no codes, and no starting.

I get dash lights except the engine light. The car cranks but nothing. From what I read online the ecu needs to be on to engage the fuel pump. You can force it to start with the relays but that’s it. Like I can put on the radio, headlights wipers etc but not Ecu as far as I can tell. I’ve tried cranking it loads of times and nothing

 

[Battoussai]

And the new ECU was programmed to your car? Or you just swapped and started the engine?

 

[sol_j]

And the new ECU was programmed to your car? Or you just swapped and started the engine?

Ohh it was an immo off one as I said. I plugged it in and there was still no engine light/ other sounds so it sounded like it was fully dead/ not even registering the Ecu at all! At this point I’m gonna get it booked in for an auto electrician but it will be a while since they are fully booked till early next month lol. It’s sad but life I guess

 

[Battoussai]

But it seems the ECU reads Cluster, Immo and Key. Even with a Immo off, the new ECU won't recognize the deleted immo and the cluster. It will mostly trigger anti-theft mode. But that it is me just wondering in theory.

You are correct leaving to the auto electrician to check that relays and ECU.

Wish you luck. Keep us posted.

 

[sol_j]

And the new ECU was programmed to your car? Or you just swapped and started the engine?

Ohh it was an immo off one as I said. I plugged it in and there was still no engine light/ other sounds so it sounded like it was fully dead/ not even registering the Ecu at all! At this point I’m gonna get it booked in for an auto electrician but it will be a while since they are fully booked till early next month lol. It’s sad but life

But it seems the ECU reads Cluster, Immo and Key. Even with a Immo off, the new ECU won't recognize the deleted immo and the cluster. It will mostly trigger anti-theft mode. But that it is me just wondering in theory.

You are correct leaving to the auto electrician to check that relays and ECU.

Wish you luck. Keep us posted.

Yeah this is what the recovery guy said:

 

[mty12345]

Did you get this sorted? Fault code points to it being a broken wire on the CANBUS wires going to/from the ECU.

One of those should match the PIN out on the ECU. With the battery disconnected, you should have continuity between the pins in the plugs for your ECU (CAN-H & CAN-L), and pins 6 & 14 on the OBD2 socket by the gearstick.

Note that if you test them, be sure to use fine tip probes to measure them! Don't push large probes into the sockets as you can spread the pins which will cause you even more headaches. IF you find you have a break in one of those wires, the the break is almost certainly going to be somewhere in the harness between the ECU and wherever it joins the main loom.

Full wiring diagram here https://drive.google.com/file/d/1PysokT7RjHc8Pr_nXBRA-lYKcS8UDmtS/view?usp=drive_link

If canbus looks OK, the check you have power and grounds at the appropriate pins also

 

[sol_j]

Did you get this sorted? Fault code points to it being a broken wire on the CANBUS wires going to/from the ECU.

View attachment 49422

One of those should match the PIN out on the ECU. With the battery disconnected, you should have continuity between the pins in the plugs for your ECU (CAN-H & CAN-L), and pins 6 & 14 on the OBD2 socket by the gearstick.

View attachment 49423
Note that if you test them, be sure to use fine tip probes to measure them! Don't push large probes into the sockets as you can spread the pins which will cause you even more headaches. IF you find you have a break in one of those wires, the the break is almost certainly going to be somewhere in the harness between the ECU and wherever it joins the main loom.

Full wiring diagram here https://drive.google.com/file/d/1PysokT7RjHc8Pr_nXBRA-lYKcS8UDmtS/view?usp=drive_link

If canbus looks OK, the check you have power and grounds at the appropriate pins also

Thanks for the reply! No I haven’t, waiting on an auto electrician to check it out. Does that mean I’d need a new wiring loom etc? Is this a common problem? Why would this randomly happen? Just old?