2004 Cadillac hesitation

Gmolds66

I'd rather be flying!
Joined
Nov 6, 2010
Messages
76
Likes
0
Points
6
#1
Hello Everyone,
I have a question about my 2004 Cadillac CTS 3.6L and wondering if anyone can guide me in the right direction. The car has the check engine light on and hesitates while driving at various speeds. The vehicle has thrown a code po205. The #5 fuel injector was replaced but the problem continues. Any Ideas or help would be greatly appreciated...thanks!
Bob
 

kev2

wrench
Joined
Nov 14, 2006
Messages
4,878
Likes
52
Points
48
Age
118
#2
Confirm location of #5cylinder you changed - not the first time we have conflicting info on cylinder numbering.

P0205 is an issue with the CIRCUIT not the component. SO did you check for voltage at inj, use a noid light to confirm pulsing?
 

Gmolds66

I'd rather be flying!
Joined
Nov 6, 2010
Messages
76
Likes
0
Points
6
#3
Thanks Kev! We did use a noid light and confirmed the number 5 injector. We are now thinking bad coil pack or bad ECM.
 

billr

wrench
Staff member
Joined
Mar 12, 2007
Messages
6,340
Likes
76
Points
48
#4
Why the coil, if the diagnostic is for the injector circuit??? Was the noid light used in parallel with the injector, while the injector was still connected? Even if it was, injector pulse-widths are pretty small, especially at idle/light load, it would be pretty hard to see correct PW with just a noid light. Point is, check all wiring and connectors to #5 injector carefully, maybe swap another injector in there, maybe run a temporary separate wire straight from PCM to injector. If nothing comes of that, and you don't have an oscilloscope available, yeah, the PCM is probably going to have to be considered for replacement.
 

kev2

wrench
Joined
Nov 14, 2006
Messages
4,878
Likes
52
Points
48
Age
118
#5
WHOA - on the condeming the PCM - Also Mr BIll asks - coiL pack? This is a COP system. 6coils..
AGAIN check the wiring at the injector...
is there 12v? unpluged - white wire is common 12v ...... tan/wht should be open - not grounded.
Is noid flashing?
on steady?
Not flashing at all?