QuestionQUESTION: Hi and thanks for your help.
Check engine light came on while driving and I noticed an odd smell like burning plastic/rubber. The radiator gauge showed high temp so I pulled into a c-store parking lot and shut off the engine. White smoke, maybe steam, came out from the engine compartment. Not a whole bunch and only for a minute or two. Got the van towed home and am trying to test if the thermostat is bad, but engine won't turn over. The radiator is full, there is liquid in the overflow, and no water on the ground; none at c-store and none at home and have not noticed any liquid on the ground when parked anywhere else.
Checked for codes, none. Tried to start, acted like battery was dying. Hooked up jumper cables, will not turn over but acts like it wants to. Removed cables and checked for codes again - got code 43 (12, 43, 55). Can't find anything in either of my manuals on code 43 specifically for a 3.8L. The gas pump does engage because I can hear it but not sure what else to check.
Can you tell me what code 43 is for a 1994 T&C 3.8L V6 and what I should do next?
Thank you very much!
ANSWER: Hi Kathy,
The 43 code means that one of the three separate spark coils in the coil pack is not responding properly to the signal from the engine controller to charge up and discharge the primary winding of the coil. I would begin by examining the wire from the spark that comes from the engine controller (the cable plugs into the side of the coil pack) to see that it hasn't been damaged over the part that you can inspect before it enter a larger harness of wires. Also take a look at the spark plug wires from the coil pack to the plugs for any signs of damage. Do you have a digital volt-ohm meter? Let me know and I can give you instructions on how to measure the three sections of the spark coil and also how to check the wires from the engine controller to the spark coil for short to ground or open connections. You might get some idea by checking when you are cranking as to whether or not there is spark at cyls. #2,4,6 spark plugs when you crank the engine over:
Just remove each plug wire, insert an insulated handle scredriver in the plug cap so the tip touches the internal connection wire, then hold the screwdriver and cap with the shaft of the screwdriver 1/4" from the cylinder head and have a helper crank the engine. See if you get a blue spark to jump across the gap or not, for each of the three wires that you test.
You may want to charge up the battery if you have a charger and it seems to be low in its ability to crank the engine. You can use the "thank/rate" to get back to me quickly for a report on whether you have the meter and the results of the testing. There is a space for comments to use to tell me.
Roland
Hi Roland and thanks for such a quick response!!! Yes I have a digital meter.
Hi Kathy,
Thanks for the evaluation/nomination.
If you look at the plug socket at the coil pack you will notice there is a dimple on one side. Consider that to be 6 o'clock. There are 4 pins in the socket:
at 1'30 is the common pin for all three coils which has 12V on it when the engine is turning over
at 4'30 is the other end of the coil for spark plugs 2 & 5
at 7'30 is the other end of the coil for spark plugs 1 & 4
at 10'30 is the other end of the coil for spark plus 3 & 6
Use the ohmmeter to measure between the common and each of the other three pins. Each measurement should be in the range of 0.45 to 0.65 ohms. See if any are outside this range or strikingly different.
Then remove the spark plug wires in pairs from the coil pack and measure between the 2 wire sockets that are paired as shown above. The readings should be 7,000 to 15,000 ohms. To check the continuity of the 4 wires at the plug, the pin that carries 12V should be connected to pin 57 of the PCM so check that connection. The pin at 4'30 is connected to pin 19, and the pin at 4'30 is connected at pin 17 and the pin at 10;30 is connected at pin 18. Remember that I am calling the clock hour positions based on the coil pack socket, so the plug side of that socket will be a "mirror image" when you look at it. Check those wires for continuity (near 0 ohm readings, and also check that they aren't shorted to ground (the engine is at ground, so the reading between the pin and ground should be either infinite or a very high number of ohms). Ideally you will find a section of the coil or a wire to be out of spec.
Roland
---------- FOLLOW-UP ----------
QUESTION: Hi Roland,
Just following up to let you know the outcome.
What happened was when my son took the thermostat out so we could bypass it and test it, he had to remove the screws from the coil pack to set it to the side so he could access the thermostat housing. When the coil pack was put back in place, we did not check to make sure none of the boots became loose. One did come loose slightly and that's why the motor would not turn over! Once the motor turned over, the radiator fan was not engaging when the a/c was turned on so we checked fuses and relays and found a bad low radiator fan fuse. Put a new one in but still no fan. Tested fan with a wire from battery to the fan and still didn't come on. LUCKILY - we had bought a new radiator fan motor assembly back in June 2004 with Ltd Lifetime Warranty so we got a new one and put it in and we're mobile once again. Replaced the thermostat too because it just wasn't worth testing at this point!
I am curious though...the fan assembly was only 4yrs old. We recently replaced the compressor and there was a new sound, like stress/strain on the motor, only when the a/c compressor is on. Could the new, not refurbished, a/c compressor and clutch cause the sound we hear and have contributed to the fan going bad? The plug-in section right behind the fan motor revealed signs of extreme heat from wiring or overheating motor - warped/melting plastic.
AnswerHi Kathy,
I am pleased that you found the cause of the no start and that it appeared to be related to the coil pack, consistent wit the 43 code.
I don't believe that the demands of the compressor/clutch would in any significant way impact the fan motor. That is something that should run continuously, regardless of how hard the engine is or is not laboring, when you have the a/c selected. I think you just had a fan motor that failed in an over-current limit draw mode that melted the plastic and blew the fuse. The drag of the compressor depends upon many variables so I would not attribute a change in sound to something that is a problem. It's control circuit is designed to be fail/safe. So I think you are ready to roll. Good sleuthing on your and your son's part! Thanks for the positive result report.
Roland
