3A05 fuel pump signal too low

deano1 · Post by **deano1** » 19 Jul 2023, 04:27

Model-2002 S60 Base m56
Issue- Hot restart.
Xemodex reloaded my CEM and this is what VIDA looks like. Disregard DDM codes as I replaced it now they're gone but plenty of other stuff to contemplate.
The 1D08 code is bad enough!
Xemodex says I should be worried about 3A05?

: Vida scan1.jpg (455.62 KiB) Viewed 1383 times

I ran VIDA the other day to try and figure what's causing my hot restart issues and these are some of the codes
I'm focused on the 3A05 code "fuel pump signal too low"
Any help is greatly appreciated.
Cheers

Post by **abscate** » 19 Jul 2023, 06:54

Get a fuel pressure gauge into the fuel rail and check it against specs, that will tell you if it’s a real or ghost code

Post by **jonesg** » 19 Jul 2023, 10:55

cheap.

https://www.amazon.com/BETOOLL-Fuel-Pre ... r=8-5&th=1

deano1 · Post by **deano1** » 19 Jul 2023, 17:22

abscate- This is a real code. After a 15 minute drive when ambient temps are north of 20 degree C. After shut down and attempted restart engine will run then stutter and slowly come to a halt. NO fuel Pump cycle when key to position 2
Eventually relay circuit will cool down and normal driving will return. Sometimes 1/2hour time elapses before I get to to driving again.
Read about that here viewtopic.php?t=100650
If you can remember I've been dealing with this for awhile and had actually put a jumper on the relay to side step the CEM in those situations. I do realize there is other wiring issues i will eventually have to deal with. This car ran very well all winter.
But, started acting up again in the heat.
Some peops here said the CEM was bad and I needed to take CEM to Xemodex.
Well I did now I have even more troubles than before. ;-(
jonesg- Cheap? Yes I am, that's why I'm here buddy

I really like the way this car handles/drives so hopefully I can save it from going to scrap heap.
cheers!
Thanks for input gentlemen.

Post by **jonesg** » 19 Jul 2023, 18:54

sounds like a heat soak issue with a component, a hot relay maybe.
you might want to try a cooling fan on the CEM.
Does that year have a PEM ?

Post by **jonesg** » 19 Jul 2023, 19:27

deano1 · Post by **deano1** » 19 Jul 2023, 19:53

I don't think there is a PEM on this base model.
Xemodex already transferred my old CEM to one of their refurbished units. I had a look under the cover of the new one and they've installed a heat sink on top of the main processor.
Fuel pump relay at CEM gets warm while engine is running and I believe it eventually gets too hot to work when restart is asked for so I believe there's too much currant at the relay.
Maybe dirty fuel filter can overwork the pump?
Already installed new pump so I don't think that's the problem.
3A05 actually means "signal too low" or "Signal to short"?
Can this be inside the CEM with "1D08 internal fault" code showing? I believe I need to check the harness between CEM and pump for voltage drop.
Thanks for throwing ideas

deano1 · Post by **deano1** » 21 Jul 2023, 04:12

Can anybody provide the wiring diagrams for this 2002 S60 m56 base N/A?
I'd like to be able to check the wiring for fuel pump circuit as well as clean/inspect all ground points.
I started with the 2 ground straps in the drivers foot well beside the CEM mounting and reset the ground points in the engine compartment fender.
Next I'd like to check resistance from CEM to fuel pump. Then check resistance of the pump itself should be 1 Ohm I believe?
Anything else I should look for?

deano1 · Post by **deano1** » 22 Jul 2023, 07:34

This might be it!

: S60 WIRE.jpg (245.41 KiB) Viewed 1286 times

Post by **abscate** » 23 Jul 2023, 00:14

Oh yeah! Nice visual clue. Inspecting wiring is one of those tasks no one wants to do when troubleshooting