QuestionHi, I hope you get a chance to share you substantial knowledge on this subject. I have read several related threads that you have handled and I think you're the guy for this one.
<<Note: I have a Chilton's for 95~98 and it has various wiring diagrams for the years. Comparing the drawing for the '95 Cirrus (the book you referenced) and the drawings for my car, it seems that where the '95 wires were orange/white (44); Grey/bk (32); and Bk/LtBlu (comm)
The '96,'97,'98 wires are Yellow (44); Blue/White (32); and Black/green (comm)>>>
'97 Sebring LXi Coupe,has been running fine at 120k miles. No start condition one morning (previous operation normal) and investigation revealed no spark. I didn't have much info at the time so I was winging it. I found that there was no spark from the coil tower and no 12V bk/rd to the coil feed, though it would "blink" voltage when the key was turned. I bypassed the ASD relay, providing 12V to the bk/rd and still no spark. A possibly related issue is that the distributor is full of oil, (apparently a seal leaking?) Due to the oil, I would have to replace the dist anyway so I installed a reman dist. Still no spark from the tower even with the ASD bypassed. If I tap the bypass wire to momentary the 12V to the bk/rd, the coil tower will fire once.
My reading tells me that the PCM controls the ground signals to the coil and injectors so the PCM is (I guess) not happy about something. This leads to checking the cam and crank sensors and I've found that there is no 8 Volt supply to the cam or crank sensors. I checked this by unplugging the 2-wire and 6-wire connectors at the dist and probing the plugs with a Fluke DVM. Yellow wire reads 0.24V. On the crank sensor, I inserted pins into each wire to check voltage there. Bk/gn reads 0; Blu/wh reads 5.0V steady; Yellow reads 0.25V. The same yellow wire reads the same voltage at pin (44). In hindsight I realize that I never did unplug the crank sensor when checking the voltage...it could be that the cps is shorted well enough to draw it down that much, I don't know. When I get back to the car in a little while, thats the first thing I'll check. The battery was removed early into this and the codes were not checked. Since that time, of course, it hasn't started and it does not set any codes while cranking that I can tell other than 12, of course.
Pin (20) reads battery voltage.
I have a new CPS in the box but don't want to install it unless I'm certain that it's necessary. (Not refundable if installed) The cam sensor, of course is new with the dist.
Several questions:
If unplugging the cps does not fix it...
1. Does the lack of 8volt supply from the PCM on 44 mean that the PCM is dead?
2. would it be possible to supply the 8V externally?
3. The local yards don't seem to have the PCM #4606813 that I apparently need...is it possible to substitute any other part# PCMs?
4. Is there a decent source for these that you know of?
Thganks a ton for reading my story.
AnswerHi Ricky,
Thanks for the very thorough report. I would pull the plug for both the cam and crank sensors and then see if you have 8V on the yellow wire, and also I would check to make sure that wire is not shorted to ground after you have pulled the sensor plugs and the ignition switch is off, or better yet pull the plug at the pcm and check that the wire is patent between the pin 44 and the yellow wires at the sensors, and that it is not grounded. There is shown to be a 10-pin connector at the rear of the PCM which has that yellow wire passing thru it on pin 5 so make sure that the connector isn't the problem (that is how it is shown in the '98 Sebring Conv. manual). I agree that unless you have 8V on both sensors you won't get any cam or crank signals and thus no spark. But before concluding it is the PCM try to unload all the possible components (which appear to be just those 2 sensors) that may be dragging it down.
I don't know the finer points of PCM numbers, they obviously are tailered to each car, trans, year, and maybe some other things too so unless you can get verification from a dealer parts counter I wouldn't try substituting. Also, don't know about sources.
I hadn't heard of the 8V supply dieing, but that doesn't mean it can't happen.
Roland
