Jump to content
SAU Community

Recommended Posts

Hi there I've currently have Error 21 (ignition signal circuit). I've also have a misfire happening only at low RPM. It will stall out if you accelerate approx 50%, if you go 75% it will drop the revs and almost stall then shoot up, but accelerate slowly it will go just as normal (these are all from stand still and rolling slowly)

Firstly the car is R34 GT-T manual running stock 
ecu 
Injectors
Turbo
Throttle body with TCS still

Aftermarket
Greddy intake
Front Mount intercooler
Splitfire Coilpacks

I've installed the splitfire coilpacks last week (brand new) along with spark plugs gapped at 0.8. I checked the coilpack loom for constant ground + 12v with the ign on and tested trigger signal for continuity from the ecu to the coilpack loom (so those have all passed) I've heard people say replace the loom but idk if thats going to resolve it for me

Injectors were cleaned and flow tested about a month ago

I've heard CAS could be a problem, I assumed mine was fine and wasn't going to be and issue. But I bought another one and it was still the same issue. Then borrowed someone's with a working one and still same issue

Hope someone has some knowledge

Link to comment
https://www.sau.com.au/forums/topic/482829-r34-gtt-error-21-misfire/
Share on other sites

On 9/18/2021 at 10:40 AM, joshuaho96 said:

The ignition signal circuit error means something in the path between the ECU ignition output to the coilpack trigger is broken open. Start with checking the connectors at the coilpacks and work backwards from there until you find it.

I guess I can put my multimeter on the ecu loom and see if there's any output voltage when the car running. But I had continuity on all the trigger wire from the coilpacks plug to the ecu

On 9/17/2021 at 9:07 PM, rahilp said:

I guess I can put my multimeter on the ecu loom and see if there's any output voltage when the car running. But I had continuity on all the trigger wire from the coilpacks plug to the ecu

The ECU sees the entire circuit path. With a smart coil the path it's seeing is ECU output -> coilpack trigger -> coilpack ground common with ECU ground. I would recommend getting a spark plug lead extension so you can put a timing light on the car and seeing what things look like on each cylinder. That will at least tell you what you're dealing with.

Also, make sure you're reading the code correctly and not accidentally flipping a code 12 into a code 21.

And continuity testing doesn't prove that the whole wire is good. You could have just one thread of copper still connected and a multimeter set to "continuity" will still beep. But that wire won't carry much current. So continuous and "functional" are not necessarily the same thing. Check resistance.

You can also measure the resistance of a single strand of copper from a similar wire and compare to a 3m length of wire to see what range of resistances could be possible, to guide your eye.

On 9/18/2021 at 2:40 PM, joshuaho96 said:

The ECU sees the entire circuit path. With a smart coil the path it's seeing is ECU output -> coilpack trigger -> coilpack ground common with ECU ground. I would recommend getting a spark plug lead extension so you can put a timing light on the car and seeing what things look like on each cylinder. That will at least tell you what you're dealing with.

Also, make sure you're reading the code correctly and not accidentally flipping a code 12 into a code 21.

Might invest in one or see if there any reputable mechanic available this week.

And its 2 short flashes pause followed by 1 quick flash

Screenshot_20210919-092320_Drive.jpg

On 9/18/2021 at 5:06 PM, rahilp said:

Thought I'd have a looking at the timing belt. And it is out by two teeth would that be enough to cause this?

16320098697796238912307621292065.jpg

Don’t think it would cause your code 21 but that is not a good sign. I would fix that before it causes more problems. 

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • My guesstimate, with no real numbers to back it up, is it won't effect it greatly at all.its not a huge change in position, and I can't see the air flow changing from in turbulence that much based on distance, and what's in front of it. Johnny and Brad may have some more numbers to share from experience though.
    • Which solenoid? Why was it changed? Again, why was this done? ...well, these wear..but ultimately, why was it changed? Did you reset the idle voltage level after fitment? I'm just a tad confused ~ the flash code doesn't allude to these items being faulty, so in my mind the only reason to change these things, would be some drive-ability issue....and if that's the case, what was the problem? Those questions aside, check if the dropping resistor is OK ...should be 11~14 ohms (TCU doesn't throw a flash code for this) ~ also, these TCU designs have full time power (to keep fault code RAM alive), and I think that'll throw a logic code (as opposed to the 10 hardware codes), if that power is missing (or the ram has gone bad in the TCU, which you can check..but that's another story here perhaps).
    • Question for people who "know stuff" I am looking at doing the new intake like the one in the picture (the pictured is designed for the OEM TB and intake plenum), this design has the filter behind the front bar, but, the filter sits where the OEM duct heads into the front bar, and the standard aperture when the OEM ducting is removed allows the filter to pulled back out of the front bar into the engine bay for servicing, a simple blanking plate is used to seal the aperture behind the filter This will require a 45° silicone hose from the TB, like the alloy pipe that is currently there, to another 45° silicone hose to get a straight run to the aperture in the front bar Question: how will it effect the tune if I move the MAF about 100-150mm forward, the red is around where my MAF is currently, and the green would be where it would end up Like this This is the hole the filter goes through  Ends up like this LOL..Cheers    
    • Despite the level up question, actually I do know what that is....it is a pressure sender wire.  So check out around the oil filter for an oil pressure sender, or maybe fuel pressure near the filter or on the engine. Possibly but less likely coolant pressure sensor because they tend to be combined temp/pressure senders if you have one. Could also be brake pressure (in a brake line somewhere pre ABS) but maybe I'm the only one that has that on a skyline.
    • Pull codes via the self-diagnosis procedure. As far as I can tell this is just a sign of transmission issues but not a code unto itself.
×
×
  • Create New...