04 Sc60 will lose power die, not start but run fine 10 min later.

Vnctvega · Post by **Vnctvega** » 18 Oct 2018, 08:30

Recently bought an 04 Sc60 for my son. Beautiful car run amazing but after driving it a while it'll start to lose power and stall. If we wait about 10 min it'll start right up and we can drive it fine again. We arent getting any engine codes. We are getting something about alarm maintenance all the time.

Post by **ndphotonl** » 18 Oct 2018, 12:39

Alarm maintenance will be the speaker unit which is failing.

About the stalling and dying; this sounds / looks like a failing crankshaft position sensor. I had this sensor failing in another type of car. It will not throw an error. The car just dies randomly and a failing crankshaft sensor is usually "misdiagnosed" as a failing fuel pump.

Whenever the ECU does not receive valid reading, it will shut down the fuel pump as a safety mechanism (in case of fire) without throwing an error code.

Vnctvega · Post by **Vnctvega** » 20 Oct 2018, 09:38

Thanks I'll check it out

Vnctvega · Post by **Vnctvega** » 28 Oct 2018, 22:13

Seems to have stopped since the weather has gotten cooler..not sure what to make of that

Post by **abscate** » 01 Nov 2018, 10:46

When my Pump Electronics Module (PEM) died it stumbled in the hot summer, cured it self in fall then finally died with a hard no-start. Back in the driveway, started fine.

Diagnostic - monitor fuel pressure at rail for spec 50 psi. No codes were ever thrown during these failures.

new part expensive - like $350

Post by **SuperHerman** » 01 Nov 2018, 11:43

I will add to the easy to check list - check your exhaust output. What goes in to combust must come out as exhaust air.

I lean towards a fuel pump related problem, but the exhaust is easy to test by hand (not exact but it is easy). If you feel it could be the exhaust, then you will have to rattle the cat(s) and exhaust by hitting them (hopefully no rattles) and then escalate depending what you find.

I had a S80 with similar symptoms which ended up being a restricted exhaust flow due to a messed up cat converter.

I had a Range Rover with similar symptoms which ended up being the fuel pump.

Your alarm maintenance is most likely the alarm module. If the board is not fried by battery acid leakage one can cut it open, replace the batteries and reseal. Plenty of write ups on it.