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Trying to figure out why car stalled while driving. After checking, there is no spark. Have replaced distributor (which also replaces coil & cam shaft), checked timing belt (by utilizing crankshaft pulley) cuz now it appears the starter has gone out (jumped starter and bendix doesn't come out to engage in flywheel). At this point, is there anything besides the PCM that could cause the problem? At a loss, and funds are scarce! And this Mom is tired of taxi-ing the daughter & grand daughter she is now supporting. HELP!
Answer -
Hi Sheila,
I feel your pain. In the course of the analysis did you or anyone else ask the PCM for fault codes? Even so, I would do it again just in case.
Try using the ignition key: turn it "on-off-on-off-on" and leave it "on" (doing this quickly, no longer than 5 seconds). By "on" I mean just the normal position when the engine is running, not the cranking position. The 'check engine'light will remain on when you leave the key in the "on" position with the engine still not running. But then watch the 'check engine' light to begin flashing, then pause, flashing, pause, etc. Count the number of flashes before each pause and keep track of the numbers. Repeat the readout and verify the counts are correct. Then group them in pairs in the order that they came out, thus forming two digit numbers. You may notice that the pause is shorter between the digits of a given number, and longer between the numbers themselves. Then send me a 'follow-up' question telling me the results of your readout. By the way, 55 will be the last number (two groups of 5 flashes each) and that is the code for "end of readout".
I have the troubleshooting manual for your engine and we can look up the possibilities of what is wrong based upon what fault codes you show. There is also an essay on fault codes at the site:
http://www.allpar.com/fix/codes.html
which gives the meaning of the code numbers. But then you need to get specific info for what exactly might be the diagnostic tests or parts to replace to complete the repair.
On the starter issue, if that hasn't been addressed, I would suggest charging the battery first, because the voltage may be too low to drive out the bendix. What with all the trying it is probably very depressed.
I hope there would be a code, like maybe an 11 or a 54, which would say that either the crank or the cam shaft sensor has gone south which will kill the spark.
So let me know if these ideas prove to be of any help. It is good that you isolated it to the spark.
Roland
Roland,
Initially we had a friend scan the vehicle (no faults). Since then the dist has been replaced (this includes the cam shaft/coil). Car still would not start. battery has been charged & the starter trouble turned out to be a fuse (thankfully). Next step-we replaced the PCM (as we thought that was the only thing left). Now have the car cranking again (but not turning over) this is actually where we started from. Now utilizing the on/off method the code we get is 12 (stating the PCM has been disconnected within last 50 start-ups). At a loss, do you have any other suggestions?
Thanks,
Sheila
Answer -
Hi Sheila,
When you say you are back to where you started, does that mean also that you still don't have any spark when you crank the engine? If that is so, then here is what I told another V-6 owner with the no spark situation (and no codes):
"I assume that you have shown that you don't have spark using a spark plug with the shell grounded to the cylinder head with the spark plug wire inserted into the coil tower (thus by-passing the rotor and the cap) while someone cranks it for you.
To check for the coil's wiring, to the rest of the system, note that there is a 6-way and a 2-way (with only 1 wire) connector to the coil/distributor. Using an ohmmeter:
check for continuity between pin 11 of the pcm and pin 1 of the 6-way (black/gray) which is the ignition coil driver wire;
check for contiunity between 6-way pin 2 (black) and ground;
check for continuity between PCM pin 6 and pin 2 of the 2-way connector (dark green/orange or black/red?) which is the ASD relay output wire;
check the resistor in the distributor cap itself:measure between the center button and the ignition coil terminal; it should be about 5,000 ohms.
You can check the primary of the coil by measuring the resistance between the socket at the coil where the single wire (black/red or dark green/orange?) of the 2-pin connector is normally connected and a ground: it should be 0.6 to 0.8 ohms
The secondary coil resistance can be measured between the coil tower and the same point as just described above on the 2-way socket at the coil: it should read 12 to 18k ohms.
Check the rotor for continuity (no resistance value is given in the manual).
While I have focussed on the coil, etc. be aware that the failure of any of the sensors could cause the ASD relay to open which would kill the spark too, so that is why you want to verify that the ASD relay is in fact closed (there is voltage at the fuel pump when the engine is being cranked, or do you have 12V on the red/black or dark green orange? wire on the 2-way connector coming to the distributor which is the ASD output voltage."
If all that checks out, and of course no spark, then we have to consider whether one of the spark-generating sensors (primarily the crank sensor) is bad, but that should
have set a fault code 11 were that the case.
If you do have spark, but no codes, then that is a different can of worms.
So check the above or tell me something I need to know.
Roland
Roland,
That is correct (the way we checked for spark)-we still do not have spark. Haven't checked the coil, but the distributor has been replaced (coil inside), have checked for fuel, checked the ASD and it's working, there's a new distributor cap & rotor. With the code 12 coming up, does the computer have to be reset somehow? Or does that mean there are no other codes which it is pulling? Is there anything else we can check (without dismantling the engine to get to the distributor again)?
Thanks,
Sheila
AnswerP.S. There is one other wire that is needed for spark: the black ground wire from pin 5 of the 6-pin connector at the distributor that goes to a bolt on the cylinder head. Might that have been overlooked? That wire is supposed to be bolted to the cylinder head at a point on the driver's side end of the front cylinder head, adjacent to the egr valve. If that isn't connected you will get no spark! Also, check the main ground wire for the entire powertrain which is a heavy black wire attached to a bolt near the rear of the trans to make sure it is tight. You have to have a complete circuit from the +post of the battery (via the ASD), and a return back to the -post, or you won't get a spark, ever.
Hi Sheila,
Well, this is an interesting problem. The computer 'reset' is only to erase stored codes, nothing else, so it's function can't be improved by any resetting process. It appears to only be showing the code 12 and nothing else. The necesssary items for spark production are: a 12V supply from the ASD relay, and a timing signal from the cranksensor, a working coil and rotor and cap and a ground for the primary side of the coil.
Do you know that the ASD is indeed providing the 12V when the engine is being cranked? That is easy to check: open the power distribution center box and find fuse #1 at the very end. Put a voltmeter on the fuse socket that is closer to the center of box (#41) and see if it comes up to 12V when you turn the key to run, then drops away after 1 second, then it should return when you begin cranking. If that happens that means that the ASD is working. Check fuse #1 because that has to pass that voltage across the socket and on to the distributor. If that is o.k. and we don't have an 11 fault code (which would be the cranksensor) then the only thing left to do is to go back to the coil/distributor and do the checks I described in my previous response (which is to check for other wiring problem possibilities between the distributor and the PCM, and the rotor and the distributor cap (although new). Then let me know if you found any problem with those checks. We can then see if the powertrain driver for the coil primary is bad.
Roland
