QuestionQUESTION: My 97 Cirrus has stopped running. We tested the pigtail goin to the the fuel and the fuel gauge has power but not the pump. We straight wired the pump and it worked. We know were not getting spark. We do not know how to check the pcm to make sure its good. All fuses and relays under the hood and dash are checked and replaced.
Through reading online, we wonder if it could be the ignition switch, camshaft sensor, or crankshaft sensor. One of which is in the distributor which came from a junkyard last year. I am trying to not buy and replace parts that won't work. Are any of these possible? Are they testable? How can we test?
There is no check engine light when we turn the key to the "ON" position, but the motor does crank normally. We tested the batter to be 13V and we have power to the main distribution box under the hood.
Motor. 2.5l v6.
175k+ miles.
Still has a full exhaust.
As far as we can tell, everything is powered and working as normal.
Thanks in advance, looking forward to your feedback.
Ken
ANSWER: Hi Ken,
The symptoms are such that it could be one of the sensors, however it also has some aspects that make me think not. The lack of the check engine light suggests a current is missing that should be going to the pcm and lighting the 'check engine' and powering the fuel pump relay actuation coil. That could be the result of a faulty ignition switch so check whether or not you see 12v on the outboard pin of fuse 10 in the power distribution center under the hood (this is the in-board most fuse in the fourth row from the front, 10 amp) when you have the key in the run and start positions. If you have 12v then check for voltage on the other side of that fuse to verify that it doesn't have a subtle crack in its wire. If there is voltage on both sides of fuse 10 then there should also be voltage on pin 20 of the pcm, so verify that point. If you don't find voltage on the fuse 10 then either the ignition switch is faulty or the dark blue wire from pin 9 of the 10-pin plug at the ignition switch to the fuse 10 in the pdc is faulty. So check the voltage at the ignition switch pin 9 (remove the undercolumn cover of the steering column). If no voltage on pin 9 then the switch is bad, and you could either replace it or try to spray some contact cleaner inside the switch using a spray can and straw applicator. If there is voltage then verify the dark blue wire for continuity.
I agree with your intention of not throwing parts at the problem.
Roland
Sorry for the delay but I just found your question in the "pool". Let me know if the voltage/fuses check out and we can go into the issue of the sensors.
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QUESTION: Is there a pin diagram you can link me to. So I know the layout of the pcm pins so I can be sure to test the right ones.
ANSWER: Hi Ken,
There are two plugs for the pcm: a plug with a black interior has 1-40 and a plug with a gray interior pins 41-80, and if you look carefully you will find engravings that show the numbering of the pins. The 12V supplies are as follows:
pin 20 dark blue/white should show 12V when the ignition is in the run/start
pin 46 red/tan should show 12V all the time (via fuse #5 direct from battery, the outboard fuse in the third row from the front)
As for a diagram, you might see if Autozone.com has it. Otherwise, let me know and I can xerox a copy from the manual and postal mail it to you.
Roland
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QUESTION: Pins tested identical to battery voltage. Is there a way to check the power out of the pcm to verify the pcm is good?
AnswerHi Ken,
Have you checked to see if the check engine bulb might be burned out at the cluster? If you can get that to work there would be a way to figure out what it wrong.
On the voltage outputs of the pcm:
44 orange/white should show 8V
61 violet/white 5V
The rest of the pins are for signal/control/ground
You can test the cam and crank sensors if you turn it over by hand with the ignition in 'run'.
The cam signal is tan/yellow on 33, the crank is gray/black on 32 and those would be measured with reference to signal ground black/light blue on pin 43. You should see the voltage pulse between 5 and 0.3V as you crank the engine by hand using the crank pulley bolt if the sensor is good.
Roland
