No Spark Caused by a Shorted Ignition Coil
This 1997 Chrysler Sebring with a 2.5 liter came in as a no start. The basic checks revealed a no spark condition. Instead of checking for a good cam and crank signal I pulled the distributor cap off to check spark right at the coil that is located in the distributor housing. With my spark tester hooked up to the coil I used my scan tool to actuate the coil spark test. I still did not have spark so I now know that I either have a coil, power, ground, or signal problem. I checked the power supply and had 12v. I than checked the signal from PCM.The PCM signal triggers a transistor in the distributor to fire the coil. Instead of using a test light like I do with other Chrysler’s, where the PCM coil driver is the actual ground for the coil, I used my logic probe. With the logic probe I could see that the PCM was attempting to fire the coil. I now knew I had a bad coil but did a current test to confirm my belief. The current test revealed a shorted coil, which you can see by how the amperage jumps straight up instead of having a nice even slope. I tested the new used coil to make sure it worked before I installed it. With every thing back in place the Sebring pop right off. Having the ability to see amperage in work really makes life easier.
Leave any questions or comments below. Thank you.
The Automotive Scan Tool, Scope, and Waveform Training Manual is just over 40 COLOR pages long and is full of images, tests, information, tables, conversions, and common problems. This manual is focused on advanced beginners and intermediate users. Advanced users would also find this manual very handy. The main focus of the manual is on scope usage, interpreting waveforms, and utilizing your graphing scan tool(s).
Great guide for Snap-On Modis, Versus, and Vantage Pro users but the manual is designed for all automotive scopes in mind. This great resource includes useful charts and tables, scope waveforms, graphing scan tool testing tips and tricks, along with scope test lead and low amp probe test hook up location diagrams. Sensor tests include O2, TPS, VSS, MAF, CKP, CMP and MAP. Other component testing includes fuel pumps, coils, starters, blower motors, and fuel injectors. Ford Mode 6 misfire diagnostics and Ford coil on plug (COP) testing tricks included. Tricks include two test lead hook-ups to diagnose how many coils and which cylinder coils are bad, even before the customer knows! Download Now – $15
stephen bell
Just to let you know after downloading your manual i throughly enjoy using my modis lab scope, keep up your excellent work.
kind regards stephen bell
Travis Dewitz
Thank you, Stephen. Once you force yourself to pull it out and get the hang of it, it really can save the day a lot.
Tom
Would you show how you hooked up the various tests to the Modis for this case study?
Thanks
Tom
Travis Dewitz
I put the low amp probe around the power feed (dark green/orange) to the coil located near the distributor connector.
Janet
I have a 1997 Chrysler Sebring 2.5 ,6v. It crank but won’t start.I drove fine the day before after I blew it out on the interstate because it had been sitting up for 11months with almost no gas. We changed the roter and cap it still wasn’t starting. No spark. Now my dad change the crank sensor. Still no fire no spark. Maybe I mixed the wirers up when I went back in to put the cap in after the roter alone wasn’t the problem. I’m a woman but im quick to learn when it comes to my any ?.
Travis Dewitz
Could be a lot of things. Do you have spark from the coil? Common coil failure on that motor. Testing wise it is all about verifying power, ground, and coil control signal. New crank sensors from a part store can be bad a lot.
Janet
Could it be the spark plugs or wires.
yohannes
i have a 1997 Chrysler sebreing im getting fuel ands its turning over
but im not getting sparke do you know why that me i was thinking it was cap and rotor
chris
1997 chrysler sebring it has 50k miles on it. has now fire no power to the coil or no power to the crank sensor
sarah
So about a year ago now i was driving my chrysler sebribg to my bros house to get looked at and it felt like i had to put more gas to get it going i let him look at it and after a couple more rides he backed it up and it never starrted again i found out that i had to get a new cam gear cause my wooddrift key fell out so i got a new one put it on replaced the balancer and the had it timed with a new belt and it NEVER started again i took it to a couple shop the told me its not an elecrical problem the otger shop got it to crank but not start i am not sure but i am think now it could be the sensor in disturbor if anyone can please tell me what it could be and not just tell me my engine is bad ( i dont think it is) please let me know thanks
marc
Distributor. Just take the one in the car out and test it first but its probably the distributor. Really. Hope that helps you and if you already found out what it was, let us know. But, again, I feel that the dist is shot. Get one from a pull it yard. Thats where I get all my sebring conv parts from including distributors, pcm’s and everything else(except ball joint/LCA’s). Good Luck!!
Allan Ingram
97 seabring convertable turn key all lights on dash come on start position nothing but emergency brake light on dash comes on just like when the alarm is active i beleave they call it a starter bypass anyway go to junk yard pull ALL the fuses and relays out of one just like it replace them with all the ones under the hood and the dash on the side by the driver door BINGO WORKED GREAT COUPLE WEEKS LATER STOP TO GET GAS GET IN SAME EXACT THING MAY HAVE TO MAKE ANOTHER TRIP TO JUNK YARD I DID HOT WIRE IT TO GET IT HOME THINKING MIGHT BE IGNITION BOX THIS TIME AT FIRST HOT WIRE IT WOULD ONLY RUN AS LONG AS THE STARTER WAS ENGAGED SO I ALSO HOT WIRED THE FUEL PUMP ON DIFFERENT WIRE
tim
96 chrysler seb convert, jxi 2.5.
No spark
No inj pulse.
8 volts on ref
toggling voltage on cam and crank ref at (back probing) PCM, cranking
zero volts at ign coil driver one, back probing @ pcm, cranking
ran when parked, no start after winter sit with battery charging once or twice a month, (did not disconnect PCM while charging)
Battery charger does allow 400 mv ac leakage.
Question is, what should voltage be at Ign coil driver one, measured while connected, and back probing at pcm, cranking, and not cranking? What value am I expecting. I’m not much at SWAG diagnostics, and like to find actual culprit, but I don’t understand what the pcm or dist is doing with this driver. I get minimal mv change cranking, with Fluke 88.
tim
Should also say, relays, powers and grounds okay. SES comes on with key on then off
Terry
97 Sebring jx started and ran fine.Next day turns over but doesn’t fire. Sounds like the same problem as the others with defective coil. Mechanic thinks its distributor but says he is not 100 percent sure. Cheaper to change coil and could solve the problem. Thanks very good info. !!!
tim
Problem found after posting. Has voltage from ignition switch with key on, found voltage fell off as switch rotated to crank. Found schematic should be reversed at feed from ignition switch, slider contact is reversed. Amended drawing to add second circuit where switch is rotated up slider contact to show feed from that (crank/start) point, and imaginary splice back to ign hot feed from switch. It is not separate circuit as in the days of voltage drop at run side to save ignition system compenents (i.e. 12 volts cranking, 6-8 volts running.