QuestionQUESTION: Hi Roland
I have a 1997 Sebring Coup V6 2.5L that will not start. The check engine light does not turn on when you turn the key on and I’m not getting any codes from a scanner. It use to start intermittingly, if you turned the key on and the check engine light came on and you could here the fuel pump you knew it would start. The last time was in April. It’s been sitting in the driveway all summer but my daughter went back to college and she needs a car. So I’ve been checking a few things. It will crank but I do not get any spark. The computer does not activate the ASD relay or the fuel pump relay... I have checked the power and grounds that go to the computer they are OK. I can ground the ASD relay from the computer connector and it will work. The fuel pump will also turn on if I ground it from the computer connector and the key is on. I’m not getting any volts at the cam or crankshaft sensors. I can get 12 volts at the ignition wire plug but only if I activate the ASD relay but I still can’t get a spark. I have continuity from the crank and cam sensors volts, sensor ground and signal wires back to the computer and also from the ASD and fuel pump relay output and input wires... I can also ground the check engine light from the computer connector and it will light. It’s like the computer is not sending out any signals. So I thought it was the computer. The local parts store sent it out to be checked first before getting a new one. It came back tested OK. What kind of signal does the computer look for in order to start sending out signals? The only other strange thing was when I tested the voltage that was coming in from the ignition output to the computer it was only 11.90 volts with the key on There was .43 volts on it when the key was off... Had the battery checked and it was no good. Put a new battery in but I’m still getting the same voltage. Is 11.90 volts enough to tell the computer to turn on? Also when cranking the voltage drops down to 10 volts is that normal? Any suggestions would be appreciated. Thanks
ANSWER: Hi Joanne,
I am impressed with your efforts so far! The battery seems OK and yes the cranking voltage will be depressed as you observed. I am concerned that the ASD and fuel pump will not do the 1 second "on" routine when you first turn the ignition switch to run, and that you aren't getting any volatge to the crank and cam sensors. You might want to check that you are getting 12V on pin 2 of the ignition switch (blue/black wire) when you have it in the run and start positions just in case that is the problem. For the ASD and fuel pump to close and remain so requires that you have cam and crank pulsed signals. If you don't have 8V on the yellow wires of those two sensors then you won't get any signals. That 8V is supposed to be generated in the PCM if it is fully powered up. The pins for the PCM that should have battery 12V are 46 (all the time), 20 (start and run) so see if that is the case. Until the check engine light is working and there is 8V on the cam and crank sensors it will not start.
Roland
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QUESTION: Hi Roland
Thanks for answering so quickly. I have 12 .5 volts at pin # 46 with key on or off. At pin # 20, I only have 11.9 volts key on only. I unplug the ignition switch and checked the connectors they looked OK. Getting 12 volts from pin #2 at the ignition switch with key on. I then check where it comes out of the fuse box B54 pin 5-getting 12 volts there also. Then it goes to a connector behind the instrument panel then out to the engine on harness B51 which is in the center console. I thought it would be easier to take the instrument panel off than the center console, but when I unplugged the instrument panel I couldn’t get it out because of the steering wheel. I plugged it back in because I was looking for the most non-intrusive way to test. Then I realized all I had to do was remove the radio to get to the wiring harnesses. I unscrewed the radio and pulled it out but couldn’t get it all the way out because of the shift handle. I had disconnected the negative battery connector because of the air bag controls in the center console so I reconnected it so I could move the shifter. When I turned the key and put my foot on the brake the check engine light came on and I could start the car. I don’t know if it was unplugging the ignition switch, unplugging the instrument panel or moving the radio. If I turn the key, then put my foot on the brake the check engine light comes on and the car will start. Obviously there is some kind of wiring problem inside the car. I’m not sure where to go from here. Sorry this is so long but I thought you should know everything I did. Any suggestions would be appreciated. Thanks Joanne
ANSWER: Hi Joanne,
And if you don't step on the brake then what?
I don't see any relationship between the brake light circuit and the ignition system. The switch powers the center high mounted light directly and indirectly it sends power to the turn signal/hazard flasher and turn signal hazard switch to apply the brake lights in a complex circuit. But none of that seems related to ignition.
So my thoughts are to look at the brake pedal lever to see if it is perhaps shorting out an adjacent wire until you step on it.
That is very interesting and I am pleased that so far you are making progress. I appreciate the detailed description and logic that you are applying to this.
Roland
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QUESTION: Hi Roland
Sorry I haven’t gotten back for a while but I went out the next day and the car wouldn’t start again even when I pressed the brake. I did everything I did before again but I could not get it to start. I checked the brake pedal but there aren’t any wires that it could short out. Checked the brake light switch and that’s ok. The brake light switch also controls the auto cruise relay which is in the engine compartment. I can hear that click when the brake is depressed. The brake thing made sense because the problem 1st started when you slowed down to stop or turn, the car would stall every once and a while. I would usually start right back up. Whenever it would stall it was always when the brake was pressed. Then it kept getting worst +worst until it wouldn’t start at all. The brake thing really had me stumped so I continued with tracing the ignition switch wire. I had 12 .41 volts on B51 Pin 11 which is right before it goes out to the engine. The problem had to be in the engine compartment. Luckily a friend of my husbands knew someone who was really good with electrical problems and he would even come to the house. He came today and did some testing. When he check pin #20 at the PCM there was NO volts with the key on. I’m not sure why all of a sudden there wasn’t any volts there I’ve checked about 10 times and it was always around 11.90 when everything else was 12.41. I guess this was just luck. He jumped the ignition wire at the pcm to the battery and the check engine light came on and the car started. Problem found. He started tracing the wire and there was power right up until it goes to a large junction box under the fuse box, when it came out there wasn’t any power. No sure where the wire was broken because he decided just to do a splice to the pcm. The car starts now every time. We had a no start problem with this car a few years ago and brought it to a dealer. They changed the pcm-still wouldn’t start. Then they changed the distributor-still nothing. Then they decide to check the wires and found one that was broken. It cost us over $1000.00 to find a broken wire. We never found out which wire it was. There were a few splices in the engine compartment. Someone had spliced the wire from the asd relay directly to the distributor, but it didn’t look professional because it didn’t have a heat wrap on it just some tape. We stopped at the dealership and got a printout of the work that was done. The wire that was broken was from the asd relay to the distributor. That wire would have come from the computer down to the same junction box under the fuse box then to the distributor. That’s 2 wires that were broken in the same area. Must be a weak spot in the car. I hope there isn’t a next time but if there is I’m going there first. Just thought I would mention this maybe it will help someone else. I’ve learned a lot about this car and how it works from this website.
Thanks you so very much for all your help.
Joanne
AnswerHi Joanne,
Thanks very much for the update. It is good news to learn that you found the problem and fixed it. I will take a look at that particular wire so I understand better what was specifically wrong about it and mark my wiring diagram as a possible weak spot in the junction box area. Thanks for sharing your experience.
Roland
