04 9-5 won't crank, some strange simptoms, help!

[DPS]

Hello, I am kind of new to the forum (yes I mean "symptoms" it is a simptom of my grades in English/spelling many years ago)
This week our 04 9-5 Arc left us sit. (167,000 miles) It was only a mile from the house. It starting running terribly, then shut off. Would not crank.
Came back about 3 hours later and it started up. Here is where it starts getting strange. It did not start or crank on first try, but the headlights came on and leveled but no instrumentation power or lights, no ACC, no SID, no radio/cd. Tried the key twice like that, on the third try everything worked and it started. Drove the mile home. Sat in the garage over night. Next day no crank, the headlights came on and leveled but no instrumentation power or lights, no ACC, no SID, no radio/cd. (The battery is up and terminals are clean.) (some times the radiator cooling fan comes on even though the engine is cold)

So I plugged in the Tech2 to see what codes I got. It said "no connection with brakesystem ECU. Check K-line and brakesystem ECU. For further information see faulttracing in WIS."

then

"One or more BUS system can not be contacted"

then it shows the following "Missing"
ACC
EHU/IHU
Airbag
MIU
SID
Trionic 7

So any ideas? (Crankshaft position sensor? Is there a way to test it?)
Thank you
Dave

[GeoffR]

Try the ignition switch.

[DPS]

After some reading, I agree, it sure sounds like the ignition switch. Just finished the long process of getting to it, got my part number (4943692) and ordered a new one, there is a new superseded design part number (32021798). When it comes and I get it installed I will post the outcome. This link was helpful with instructions to get to the switch. https://www.saablink.net/forum/perfo...htm#post646988

Thank you!!

[DPS]

New superseded design part number (32021798) installed. Started right up, everything back to normal. New part looks more robust.

Thank you!!
Dave

[nordwulf]

Good to hear the new switch fixed the problem. And thanks for reporting back with the information that may help others in the future.