94 Accord intermittently won’t start and has Code 15. I clear the code, but always a code 15 when this problem occurs. It actually starts, outpaces the starter and is running, but when I release the key back to the ?on? position, the car shuts down. If I try to start it again, without first turning the key to the off position, the engine turns over, but never starts to outpace the starter, so I must turn it to the ?off? position, then retry and it again. Usually occurs after sitting in sun when cabin is hot, but occasionally happens when cabin is not hot. This problem is NOT related to engine being hot. About 5 or 10 minutes after opening windows and doors the car will start, as though something in the cabin has cooled down. I have replaced the ignitor and the ignition switch and reflowed the cold solder joints on the PGM-FI relay. I also had my daughter remove the PGM-FI relay and take it into class with her, then plug it back in after class and she still experienced the no start condition until the cabin cooled for 5 or 10 minutes, so that seems to rule out the relay getting too hot. I’ve jiggled every connector I can find and brushed and cleaned the battery terminals and all the grounding straps I can find under the hood. Fuel pump runs fine and supplies plenty of pressure and there IS spark and compression when the no start condition occurs. I?ve not found a way to duplicate the problem when it is working fine. I?m suspicious of the (ECM), but it?s so intermittent I hate to spend the money. We?ve had such little rain this year, but it seems to be occurring when it?s humid and/or raining outside, as the problem has occurred both times it?s rained in the past few months. Fuel pump works as it should.
It appears that code 15 is for a bad ignition output signal. The ECU may be looking for the signal to set the timing. You may be able to find a troubleshooting procedure in a service manual for error code 15.
I’ve done all the troubleshooting per the manual. This is beyond where the manual can help me. I’m hoping someone has experienced this type of symptom before.
Even though there is spark occuring when the trouble happens, I wonder if the timing is correct when the trouble does occur. If you have a timing light you may want to check the timing before the trouble occurs to have a reference for when it does happen.
The difficulty with an intermittent problem is that it’s not being intermittent when it’s working, and you’re testing it! It’s like trying to hit a moving target…difficult, if not impossible.
I’m aware of the PGM-FI relay. Here is an article about it: http://www.marklamond.co.uk/tech-honda/pgm-fi/pgm-fi.htm . When the page opens, in the menu, click on Main Relay. As you can see from the schematic, the relay has two contacts which close, make contact, and maybe send current to the 1. fuel pump, 2. ECU. And there’s the rub. Contacts can transfer current, or maybe not. Contacts always arc, burn, and pit. So, that sometimes they will transfer current and sometimes, not. Also, the coil(s) may pull in to close the contacts, or, it may not. This may be one of those times when you can’t fix the relay. It’s about $60 for a replacement PGM-FI relay.
The ignition switch (NOT the lock cylinder) has several sets of contacts. It, too, can have intermittent contacts which transfer (or, not)current to certain circuits. You could consider changing it, also. It has had thousands of actuations in which to arc, burn, and pit the contacts.
This Web site could help you: http://www.tegger.com/hondafaq/startproblems.html
I believe I’m going to take your suggestion on replacing the relay, as I’ve already replaced the ingnition switch. I’ve heard so much about folks replacing the relay and still having the problem, but that’s probably the best option for me at this point. Thanks!
It sounds like this could be a cold start flood. Have you tried a flood clearing after the engine outpaces the starter but does not stay running? Push the throttle pedal to the floor and crank while holding it there. If you get a catch, taper off to a high idle then let it settle to curb idle. Let us know the ourcome.
Researcher,
Good morning! Had the problem again and holding the pedal down made no difference in the behavior. I’d replace the relay, but every test of it always produces the correct “click sequence” when turning the key on to run, then start. I always hear the fuel pump at the appropriate times as well. What do you think the possibility is that its the computer. I hear failures are rare, but I’m about to lose my mind with this car. Every time it won’t start, it always has spark, fuel pump sequence is fine and it throws a code 15. Thank you!
You may be getting a relay “click”; but, that doesn’t mean that the current (and voltage) is making its way through the contacts in the PGM-FI relay. To check that, put a voltmeter probe on the output wire to the fuel pump, and the ignition. Actuate the ignition switch a number of times while you watch the voltmeter. If it doesn’t indicate 12 volts, check the voltage IN for each power circuit to the PGM-FI relay.
You’ve not made reference to actually using a multimeter, or wiring diagrams. Maybe, you have have a friend who will?
The problem you are having sure has the signs of an intermittent relay. If you haven’t replaced it yet I recommend you try it.
I have the same problem with my 90 it finally quit on me with no spark to distributor repalced main relay nothing plus I have no lights showing on the dash when cranking over.
I posted a reply to this once but somhow it disappeared. the following is from a 93 Prelude service manuel. Check to make sure your wireing corresponds to the following before doing any of the below!
The Malfunction Indicator Lamp( MlL) indicates Diagnostic Trouble Code( DTC) 15:
A problem in the
: Ignition Output Signal circuit.
- The MIL has been reported on.
- With service check connector
jumped, code
15 is indicated.
Do the ECM Reset Procedure.
Restart the engine
Do you have MIL indicate code 15? If no you have an intermittant failure. Check for poor connections or
loose wire At C433 (located at
right shock tower). C126 Ignition
Conlrol Modulo(ICM) and ECM.
If you have code 15 then turn ignition switch off
Remove the two pin connector from your distributor
Turn the ignition switch ON.
Measure voltage between YEL(+) terminal and body ground.
Is there voltage? If yes
Turn the igniition switch OFF.
Reconnect 2 pin connector
Measure voltage at
ECM at pinout A2l(+) and A22(+) to pin A26(-)
is there approx. 10 V? If yes then
substitute with a known-good ECM
and recheck. If symptom goes away, replace the original
ECM.
If no test the ignition coil. If the ignition coil is bad replace.
If ignition coil is ok then repair open in YEL wire between twopin
connector and ignition coil or repair open in BLK/YEL wire between
the ignition coil and ignition switch.
If after reconnecting the 2 pin connector and you
measure voltage at
ECM at pinout A2l (+) and A22 (+) to pin A26 (-) and you don’t have 10 volts then
Replace the lCM or
- Repair open or short in YEL/
GRN wire from ICM and ECM
NOTE: lf the YEL/GR wire was shorted.
the ICM may be damaged.
ls the ignirion coil OK?
Hope this works for your car!
In re-reading your posts, it’s plain that you WON’T use a voltmeter on any electrical circuits. That leaves taking the car to someone who will. That person could check the ignition control module in the distributor. This test, which is simular to the test listed by Skypilot, is in Haynes Honda repair manual #42013, page 5-5. It’s unlikely you’ll find the cause of the problem without doing some electrical tests.
Thanks folks! Hellokit, suppose I failed to mention I’ve been through this car head to toe measuring voltages, conductivity of wires and analyzing signals on the oscilloscope. I’ve measured every voltage and waveform you can shake a stick at related to this problem. My Haynes manual is the dirtiest book on the block. I’ve read as many internet postings claiming “replacing the relay fixed it” as I have “repalced the relay, but still have the problem”. So, go get your book and follow along…Page 12-18 in Haynes Manual…Hot At All Times = 12.5v at C430/7…Key on = 12.2v at C430/5 (also at start) …12.25v at C430/6… 0v for 2 seconds then 11.9v at C430/1…Key at start = 10.24v at C430/2…0v at C430/3…12.25v at C430/6…10.1v at C430/4 ---- Page 12/20 Hot At All Times = 11.6v at C125/2 & C125/5…Key on = 10v at C458/11 & C124/1…Key at start = 10v square wave at C458/11 & C124/1…pulsing wave on all injectors (can’t recall the voltage dropped by the resistors which are all OK on ‘out of circuit’ ohm test)…0 ohms from C458/11 to C124/1 and from C125/1 to C134/6. And these all are present whether it will or won’t start. Nothing changes. Code 15 is the key. The only way I see the PGM-FI relay causing a Code 15 is if the 12.25v at C459/13 “ECM Power Input” somehow dips too low, but I’d suspect that would be throwing all sorts of codes instead of the same code all the time. Please help me understand the specific rationale on the PGM-FI relay throwing a Code 15. Thanks!
Since the engine is shutting down when you release the key to the RUN position have you checked for a connection problem between C906 and C402? They are near the ignition switch.
Part of the problem is knowing how the engine computer has detected a problem. What circuit does it get that information from?
Referring to page 12-20, in your handy dandy Haynes, we see that the “primary output control” from the ICM (Ignition Control Module) leaves via the Green wire to the ignition coil. Since it’s known that ignition coils can develop weaknesses, and misfire, my vote is with a defective ignition coil. It’s possible the ECM (engine computer) has intermittent “ignition input signal” causing intermittent output…
If you wanted to, you could connect an inductive pickup to the yellow/green wire, connect to an O’scope, and monitor the ECM signal while the engine is running. Also, the green wire’s signal for “primary output control”, could be monitored.
Auto Zone list the ignition coil for less than the entire distributor.
Added later: http://www.tegger.com/hondafaq/badsecondary/internal-arcing.html Check these pictures for a visibly damaged ignition coil.
The moral: Don’t crank your engine when the distributor cap is off!
Hello Hellokit,
I replaced the PGM-FI relay several months ago and still have the same periodic no-start symptoms on hot and/or humid (rainy) days, such as today in the Atlanta area. However, today the car started (1st start of the day) but died when my daughter put it in drive. She has described this symptom before, but today is the first time I’ve been around to actually witness that symptom for myself. I started it and reproduced the same symptom; although, eventually it began to die on me while still in park…(I think that was due to it warming up and the initial ‘cold engine’ high idle settling down) I observed that, no matter what gear I had it in, if I kept the RPMs over 1,000 it would stay running. As soon as I let the RPMs get down to 1,000 (on the tach on the dash), it would die immediately every single time. Remember, within the last year, I’ve replaced the ignitor, ignition switch and the PGM-FI relay. Any ideas on that?
Anybody have any ideas per my last post on 7/13? Looks like Hellokit is not around. Car runs fine this evening.