Hi, All!

1998 Boxster 986 (Base 2.5, manual, and so on).

I recently replaced my failing battery that was just about out.

Haven't had any moisture issues or anything like that. I keep her in my garage and check my drains regularly.

Had her since 2013.

Once I installed the new battery she suddenly just won't crank. Never had this happen before. No solenoid problems or anything.

Tried swapping in another known-good battery to test, but same results.

Everything seems to work except actually starting.

The old battery was DEFINITELY being an issue. I threw it back in temporarily to see whether I got anything, but only the kind of flickering lights you get from a mostly-dead battery.

Hooked up my ancient Durametric and I got a set of Alarm codes:

Current Fault Codes

21
No engine start possible
W lead (DME immobilizer) open circuit
Status: Not present
Number of times DTC present: 1

49
No communication with PST 2
This fault is stored if the K-lead is short to ground
Status: Not present
Number of times DTC present: 8

23
W Lead
DME Immobilizer short to B+
Status: Not present
Number of times DTC present: 3

25
No terminal 86 S Recognized
Check fuse F 5/1
Status: Not present
Number of times DTC present: 2

42
No engine start possible
Wrong key or wrong transponder pill
Status: Not present
Number of times DTC present 1

Pulled the left seat and examined the immobilizer- No dampness, signs of rust, nothing. Vacuumed up since it was dirty. Fuse is fine.

I haven't gone ALL the way through the entire fusebox yet but I think I hit all the ones that are DME or alarm related. Nothing looks blown, but I can definitely pull them all and check.

Just off that set of codes and the behavior mentioned would anybody have ideas?

My key is still the original. It just hit me that I ALSO have the valet key, so I'll give that one a shot.

Thanks!


Durametric Alarm Codes

 

Check the clutch interlock switch? That will cause a no crank situation…

 

if you are pulling the fuses to visually check them, you might want to pickup some DeOxit and hit the sockets with a spritz.