Expert: Roland Finston - 9/4/2011

Question
QUESTION: Hello,

I have a 98 Chrysler Cirrus, 2.5L that will not start. Here is a brief history of what we have done so far.

First, the vehicle died and upon examination determined the PCM was bad. We had the vehicle towed to an auto electric shop where they confirmed a bad PCM. We ordered a remanufactured PCM from Autozone, and Voila, ..problem solved.......for about a week.

Then the vehicle started stalling randomly and having intermittent power losses followed by rapid recoveries until it finally died all together. Upon examination, when the key is turned to the on position, you can no longer hear the fuel pump turn on at all. This is quite evident as this vehicles pump is very loud normally.

SO.....we replaced the fuel pump and filter while we were at it.....and still no fuel pump turn on and no fuel at the rail of course.

SO....pulled the spark plug to check for spark....NONE!

SO.....Replaced CPS (Crank position sensor) .....No Change....


At this point I suspect a defective PCM from AutoZone but if not....I am fresh out of idea's!


Can you help........Please???

ANSWER: Hi Todd,
Did you look closely at fuse #8 (20 amp) in the power box in the engine compartment. It may have a crack that caused the intermittent and final failure of power for the spark and the pump. Other than that we will have to check some wiring for voltage. Verify that the fuse shows 12v with the ignition switch in the 'run' position. If the starter is working though, then that fuse is OK. If the fuel pump won't run for about a second check to see if the fuel pump relay in the  power box (third socket from the front 'click' on and off in about a second when you turn the key to run. If it doesn't then check fuse #10 in the box. Let me know what you find. At that point a defective pcm is a possibility.
Roland
PS Sorry for the delay but I just found your question in the 'pool' to which it had been referred by Kevin. Please 'rate' my answer and where you see the question about a nomination of me to be 'volunteer of the month' consider a 'yes' response. Thank you

---------- FOLLOW-UP ----------

QUESTION: Thank you for your reply and help Roland.

Yes, I did check all fuses and relays, sorry I forgot to include that in my initial description. I even traded places with several relays and fuses just to test them, such as the auto shut off, fuel pump relay etc. All apear to be working fine. There is zero sound or effort from the fuel pump and no spark too.

Battery is strong and starter cranks away. This is why I remain ......Puzzled!

Answer
Hi Todd,
When you turn the key to the run position do the ASD and fuel pump relays click on and then off after one second? If not, is there power on fuses 8 and 10 at that time? If there is power to the fuses and the relays don't click then the PCM is not working properly. Check that there is power on plug pin 20 at the PCM dark blue/white at that time, and also verify that there is power on pin 46 at the PCM at all times (red/tan). Finally check that the wires on pin 10,47,50 of the pcm plugs show continuity to ground. If all that is correct then I would believe the PCM is bad.
Roland