Diagnostic Codes 14 and 43 - Intermittent failure to start, cranks ok

[suprarx7nut]

Alright SM guru's. I come to you seeking some knowledge. I have an intermittent starting problem with my 7MGTE. It's embarrassing and I can't seem to track it down.

Overview: Car will always crank ok, but will occasionally fail to start. This seems to happen more when it is hot or warm, but has also happened after sitting in cold weather for over 8 hours. The car has never stalled while running, the problem appears to only be present while trying to start. I get both codes: 14 and 43.

Troubleshooting Performed: I've gone through all the TSRM testing I can find that may be related. I've tested the igniter, ignition coil, ECU, all wiring back to the ECU and replaced the CPS with a reman unit. All tests pass.

The two codes don't seem to have much in common.

14: Ignition Signal. No IGF signal to ECU 3 times in succession.
43: Starter Signal. No STA signal to EDU for 8 seconds when engine speed is between 2500 rpm and 4000 rpm and coolant temp is below 80C and NSW is off.

43 Doesn't make a lot of sense to me. I've never had a problem cranking and I haven't pop started the car since I cleared codes last. 14 sounds like it may be the igniter, but it is passing all tests and hasn't failed on me while driving. I'd think a bad igniter would go bad while driving as well as while cranking, but perhaps that's wrong.

Do these two codes share a common potential fault I'm failing to see? I'm coming up with nothing and although I've enjoyed learning how to perform a handful of new test procedures I'd really like to just get this figured out.

Any help is appreciated. Thanks guys.

-Andy

Update: Problem was resolved with a new battery and grounding the igniter. I can't explain exactly how the battery would fix the no start condition, but it appears to have fixed it.

 

[Nick M]

43 doesn't mean you have a problem cranking, it means the ECU is not seeing 12v applied to the starter with the ignition circuit in the crank position. STA makes sure the injection and spark timing are altered for cranking speed and because there is not yet a usable engine speed and load signal.

14 means there was no spark confirmation. That doesn't mean there is no spark, it means there is no spark confirmation. When the transistor operates the coil, that is the electrical signal sent for spark confirmation. The ignitor outputs that IGf when it sees that signal. Either there was no spark, or the light green wire with the black tracer is not complete from the ignitor to the TCCS. This can be something as small as the pin is bent when the connector was pulled off and on a bunch of times. I don't know that you did that, but that is all it takes.

Hard hot starts is usually vapor lock, even on an EFI car. You can always check your spark plugs to see if they are wet with anything when cold. Don't forget to check for spark at a plug, in reference to code 14. I would have to look in the EWD but I think you need the STA to operate the cold start injector.

 

[jetjock]

^ What he said although based on the no start I'm guessing there really is no spark. Check for that first then check for IGf integrity. And remember, no IGf very quickly = no injection.

 

[suprarx7nut]

Thanks for the feedback guys.

During my initial troubleshooting I watched STA as I cranked but the voltage moved around enough that my old fluke only displayed a couple voltages during the crank. TEWD/TSRM states it should be 6-14 and I only registered 4-5V while cranking. I thought it was just the display of the meter having trouble keeping up, but perhaps that's a part of the problem.

The wiring is all brand new and I made sure to use 12 AWG for the STA wire. I wouldn't think that'd be the problem, but I'll trace it back and see if I can see any unusually high resistance in that circuit.

I checked the IGF wire from the ECU connector to the engine bay connector for the igniter and couldn't get any faults by twisting the wiring around.

I just pulled the igniter off and it's dirty inside, but not awful. I will clean that and add the extra ground wire just in case.

I'll inspect the interior side of the STA circuit and see if I can watch the voltage any better further upstream. Maybe the circuit is ok up to the Starter Relay or Circuit Opening Relay. That'd at least give me a starting point.

Thanks for the tips Nick and JJ.

 

[3p141592654]

This is a case where a simple test light may be better than an old DVM. Hook the test light to STA and ground at the ECU connector, and it should light when the key is in start. The actual code 43 is set if the engine speed goes from 0 to > 800 rpm (with car not moving) and the STA signal is not detected. The ECU interprets this as the car being started without the STA signal present, so sets a code.

Anyway, should still start without STA, so code 14 needs to be troubleshooted. It is much more serious. I hope you didn't replace the CPS because of a code 14.

 

[suprarx7nut]

Pi, thanks. I didn't replace the CPS because of the code 14, but the code 14 led me to test the CPS, which tested bad. The G1 coil had resistance greater than a couple megs. The CPS was also leaking through the shaft even after I attempted a seal replacement. It was time for that to go, the 14 code just helped me finally man up and buy a replacement.

I can rig up a test light with an LED and a resistor that together would require 6V to light the LED. That sounds like a great plan.

For the Code 14, is there a way to test the igniter for that function specifically during cranking? I followed the TSRM, but nothing seems to come up for that wire. The tests utilize every wire but IGF in the ignition section. In the TEWD there's a test for the IGF at the ECU, but it only has parameters for idling, IG switch on and after shutdown. I didn't measure on shutdown, but idling and ig sw on passed their tests.

It just seems so odd that the problem only occurs during cranking. I've never had the engine die while running, but it will fail to start about 10% of the time now. I haven't noticed any pattern. It will happen when hot, warm, cold, on a hill, flat, when the moon is waxing, waning or full.... etc.

I'll see if I can get some garage time tonight to tinker more with it and report back soon.

 

[3p141592654]

I suggest you monitor cranking voltage (at coil B+). On another car (more modern) the cars ECUs were going crazy and setting all sorts of weird codes that could not be traced to any fault. Turned out the battery had a bad cell and was dipping below 8V during cranking, causing the ECUs to reset randomly.

In your case, the voltage may dip enough during cranking that the spark is going out. The real way to test the IGf signal is to put it on a scope. Monitor IGt and IGf and you should see a blip on Igf at every firing.

 

[suprarx7nut]

I suggest you monitor cranking voltage (at coil B+). On another car (more modern) the cars ECUs were going crazy and setting all sorts of weird codes that could not be traced to any fault. Turned out the battery had a bad cell and was dipping below 8V during cranking, causing the ECUs to reset randomly.

In your case, the voltage may dip enough during cranking that the spark is going out. The real way to test the IGf signal is to put it on a scope. Monitor IGt and IGf and you should see a blip on Igf at every firing.

My battery is a Die Hard Platinum that has been great up until this winter. It had some trouble holding charge over the last few months likely because the car sat for pretty much all this winter and wasn't driven or disconnected. Now it seems to die off rather quickly.

You may be onto something... I'll monitor B+ during cranking and see what it shows.

 

[suprarx7nut]

Results on +B:

Ignition SW on - 11.1V
Cranking - down to ~7.5V

Results on STA tonight:

Cranking - Erratic down to 4V went from OL to around 4V to OL, back to around 4V then the car started.

During both start attempts the car took a couple seconds and started. Pretty normal healthy starts disregarding the DMM measurements. The DMM results are a bit shaky because the values change so quickly and the display struggles to keep up. I'm using an old Fluke 77. I have an 87-V at work that I'll have to borrow this weekend to see if the results look different with a more modern, calibrated DMM with a good display.

Igniter removal revealed the inside of the igniter is a little ugly. Some residue and corrosion, especially around the B+ terminal which is no surprise. Given the potting in the igniter I'm not sure if the corrosion seen here is concerning or not. Any ideas?

 

[Nick M]

I suggest you monitor cranking voltage (at coil B+). On another car (more modern) the cars ECUs were going crazy and setting all sorts of weird codes that could not be traced to any fault. Turned out the battery had a bad cell and was dipping below 8V during cranking, causing the ECUs to reset randomly.

Common rail Ford diesels act pretty stupid when B+ dips. And when it dips far enough, a relay opens. So, yeah, pretty much.

 

[suprarx7nut]

Mixed news this weekend. I got a new battery. I took my old one to get tested and it failed so I got a free warranty replacement. Woo!

Bad news, however, is that even after the new battery I got a code 43 after one start. I obviously have another problem causing the STA signal code. I drove the car this weekend for a few errands. It started every time without problem. Code 43 showed up right away every time, but 14 never came up. The car also idled around 1200-1500 RPM which is odd. I've never had idle issues with a 7M (GE or GTE). Driveability is great, no issues at WOT up to redline, AFRs look normal.

I added a ground to the igniter, but I have no idea if that will help anything.

Ugh. The frustration continues. I'm going to start driving it everyday to work this week. I'll keep the glove box removed and my DMM in the car. If it fails to start I'll run through troubleshooting in the hopes of finding a failing test result while it's actually failing to start.

Is there any way to test the ECU itself? It seems like an unlikely suspect, but mine is pretty physically damaged. The casing is dented in a few spots.

 

[3p141592654]

Good progress. First thing I check with high idle is a code 51 due to bad or out of adjustment IDL signal.

 

[suprarx7nut]

Update: With the new battery it's started everytime, no problem about 14 times in a row. The failure to start seems to have been battery related. I still get a code 43 and I need to troubleshoot that, but it's functional now.

The idle also seemed to fix itself after the first two days of driving. It seems weird that the ECU would need that long to "learn", but could that be it? I thought the ECU only took 30 min to an hour to learn. :dunno:

 

[RiyadYar]

hows the car been holding up .still no shutdowns? im having the same check engine codes and symptoms even after i changed my battery

 

[suprarx7nut]

hows the car been holding up .still no shutdowns? im having the same check engine codes and symptoms even after i changed my battery

Haven't driven it for a week while I get a bent wheel and my power antenna repaired. The battery seems to have solved the 14 code, but 43 still shows up every crank.

I'll update again once I start daily driving it again (Hopefully within a week).

Are those your only codes?

Sent from my Moto X.

 

[Nick M]

The battery seems to have solved the 14 code

I don't think that is possible

but 43 still shows up every crank.

That only shows up if you crank the engine. Without the STA signal of course.

 

[RiyadYar]

yes, those are the only codes I have like you ive rebuilt the cps and added another ground to igniter, i also changed the battery. the car starts pretty much 90% of the time it has also shut off and refused to start for a couple minutes at a stop sign once . i was thinking the sta signal code was because i've done the 12volt relay starter mod so was considering ripping it out and im thinking it was the coil packs that are going bad after checking resistance between terminals as per tsrm they were a little out of tolerance so i was going to do the moganson cop upgrade to see my results. still have yet to calibrate the tps but will do once i get to work on it again

 

[suprarx7nut]

I don't think that is possible



That only shows up if you crank the engine. Without the STA signal of course.

Yeah, the 14 code disappearing and battery change could be coincidental. I also added the igniter ground. I'll keep this thread updated, but so far it seems incredibly coincidental that it has started 100% now and before was somewhere around 75%.

The STA thing is still strange. I measure just under the TSRM spec at the ECU with a slow DMM. I'll try to remember to borrow my newer Fluke from work and try to get a better measurement. The engine side wiring is all new and I used 14 AWG which seemed larger than the factory wiring.

Perhaps the wiring to/from the starter relay or the relay itself is a source of resistance?

 

[suprarx7nut]

Update on this issue. My codes have been 100% clear since the battery replacement and igniter grounding. I drove the car all summer daily with 0 issues. I can't explain it, but the battery and igniter seem to have solved my issue. I stopped checking codes once it started reliably again so 43 may still be there, but if it is there it seems to have no bearing on performance or reliability.

 

[jetjock]

Thanks for the update. Fwiw a healthy battery will not sag below 10 vdc under cranking, about the same voltage it should never be discharged below to avoid impacting its service life.