Engine Check Light still coming on after Distributor has been changed(TDC Sensor Flty

[Egxris]

Hi Guys.

Every now and then my car took an extra turn over to start(B18C2 in a EG Civic), engine check light would come on and it would throw up an 8. TDC Sensor. So i bought a brand new item from the states and put it in. No more problems with it starting or bringing up the light.

......or so i thought.


that night i was slowly crawling through peak hour traffic and the light came back on. Sure enough when i had a chance to stop it was the TDC Sensor Faulty again WTFFF?? :thumbdwn:

so i thought it might be just the ecu needing resetting memorising the old problem. so i left the battery off over night/did the two terminals together trick.

Still fkn comes on but only when the cars sitting there not doing anything running... (and it has to be after a bit of a drive).

Took the car to the hills drove the shit out of it. no light came on. parked at the top sat it idling and BAM the light came on. Turned the car off then on (no sign of needing to extra crank no sign of any problem) and the light goes out.

Any ideas on why this POS is throwing up the error code? Just annoying having this light come on when there seems to be nothing wrong with the car.

thanks

Neil

[Egxris]

So it started to do limp mode again...pulled it out put the old original faulty unit in and it worked. Looks like I wasted $200 on a dud. Now to warranty claim...

[henrygiang]

check your wiring if youre using a hondata/obd2-obd1 wiring harness. pretty much the exact same thing happened to me. was getting TDC error code too. removed hondata and plugged in a standard ECU and it disappeard. most likely your wiring somewhere

[Egxris]

Nar its the sensor. When the light comes on its harder to start. the new unit the light came on after awhile (different to the oem one which only came on with alot of stop start driving (turn off and on again) when it got hot then it would take an extra crank to start. so def the dizzy. new one light came on when you left it idling (no problem starting it though) then. it wouldnt rev past 3000rpm (limp mode) and started stalling (def the dizzy). so yeh. if i get another one and the light comes on again i will 100% be getting the wiring checked.

[ECU-MAN]

Hi

Its comon with rebuild or aftermarket dizzys to have this problem. To correctly diagnose you need an oscilliscope to view the waveform of the TDC. It may be putting out the correct signal but with noise or the edge is a falling edge not rising edge ( this means TDCP and TDCG are back to front. )

inspect your TDC reluctor and Pulser for any cracks, metal fragments or signs or damage. Sometimes the airgap is out as well. Also double check your wiring and try a known good ECU. I have seen failed ECU's in the past that can cause CYP TDC and CKP codes ( if its your ECU it can be repaired )

check out this link
http://www.ozhonda.com/forum/showthread.php?67779-DIY-PGMFI-Diagnostics-Code-8-TDC&p=1188961#post1188961

[Egxris]

So what happens if its the brand new distributor? replace? its not a fixable thing is it. and since two different dizzy's did 2 different things id say its the dizzy's that are faulty (never went into limp mode with the OEM one only the new one.) not the ecu.

[ECU-MAN]

is it a new OEM or New aftermarket dizzy

I cant tell you what you should do with out diagnosing the issue with the correct tools.

if you cant get access to the tools required to correctly test for the fault, you need to try known good parts untill you find the issue.

it may or may not be your Dizzy

[Egxris]

dizzy is a new aftermarket item.

[ECU-MAN]

if in fact your new Dizzy is at fault, you might be able to fix it with the parts from your OLD Dizzy.

you can use the working CYP from the old dizzy as the TDC on the new dizzy

However I think it is to coincidental that two dizzy’s gave you code 8. I would be looking for a wiring fault or at the ECU first before touching this new dizzy.


I forgot to mention that temperature can effect the Dizzy and or ECU when they play up. you can get different results with different temps.


If you can open your ECU and take a good quality photo of the inside. post it here, I might be able to see if it has failed.

[Egxris]

thanks for the help. im waiting on the joint who i got the dizzy off to get back to me re warranty/replacment and i'll then go from there. I know it seems sus that both threw the same error but are behaving differently.

[ECU-MAN]

doesnt mean much. you may have disturbed somting that would create a different result. so many varables with the unknown



good luck with it

[Egxris]

true. hate electrical gremlins

[henrygiang]

mine was exactly the same as you mate. it would start fine one day, then the next time i went to start it, the number of cranks before it would start increased to the point where it wouldnt start. i replaced the dizzy, thought everything was all good, then got a check engine light again.

it was the dodgy odb2-odb1 wiring harness that was the problem. i dont think my dizzy was ever the problem :|

also only began after i got a hondata s300 installed too so everything points to the wiring harness.

[Egxris]

Thanks mate. Do you know where i can get a new harness from? How do i tell which harness i have? if i take a photo can people tell me which one i have/need

its running a B18C2 engine(if that helps?)

[Egxris]

Heres the loom ive got/ecu anybody able to tell me what it is from this pic?

http://a7.sphotos.ak.fbcdn.net/hphotos-ak-ash4/432262_10150539084792539_738212538_8673659_9158262 33_n.jpg

[ECU-MAN]

OBDI car, OBDI to OBDIIa convertion harness OBDIIa ECU

you best perform a continuity test from the dizzy to the ECU connectors to check for wire breaks,

get an OBDI ECU and start the car, let it idle. doesnt matter if its a D15, D16 or B16 ECU as losng as you dont drive it. Do you still get code 8 ? if not then its the convertion harness or ECU, if so then its the dizzy or wiring. I put my money on the conversion harness as mentioned before.

[Egxris]

Now the question is does anyone have one they can let me borrow(in melbourne) to see if thats my problem??

[Egxris]

Just double checking this is what id be looking for

http://ep.yimg.com/ca/I/yhst-36489773463283_2193_37144418

This unique ECU jumper harness converts from OBD1 to an OBD2A ECU. This is ideal when installing an obd2 engine into an obd1 chassis when you want to use the obd2 ECU.

i noticed it says - On certain applications, you may need to wire additional sensors into your harness to eliminate all Check Engine Light codes as OBD1 chassis do not have all the required sensors that an OBD2A ECU looks for.

Ive got a mate lending me a B18Cr ecu will this be ok to test the car?

Also which brand would you suggest would be the best one to get as the push on solder type i just dont like the look of (the one i have atm). As its just sitting under the carpet of the passenger side im pretty sure from feet something may have been dislodged.

http://www.boomslang.us/obd1to2.htm <--the best out there? most expensive $125usd
http://www.rywire.com/catalog/obd1-to-obd2a-ecu-conversion-harness-p-12.html <---looks to be push on solder type$100usd
http://www.robearracing.com/pd-zerg-ecu-harness-obd1-to-obd2a-conversion.cfm <-- Zerg? cheapest at $98usd

Thanks again for the help!

[ECU-MAN]

A type R OBDIIa ECU will be fine.

your exsisting conversion harness can be repaired. no point getting a new one, resolder the dodgey or broken wires. with cheep ebay harnesses, I resolder all the wires as they look like they are made by some kid working for 3c a day.

[Egxris]

ok thanks mate. i'll redo/check all the solder joints first then go from there.

[Egxris]

So finally the warranty replacment turns up for the dizzy, installed it tonight turned the car on with the plug jumpered and the code 8 is there flashing. Set the timing turned the car off, unjumpered the plug started it no errors drove the car then suddenly limp mode and the car starts to stall. Pull the new dizzy off throw the old one back on and it works fine..... Both new dizzys do the same thing?!?! So they can't both be faulty. Am I missing something when swapping these over?? Should the ecu need to be reset first? Is there a special process to follow when changing dizzys on a Honda engine???

I checked the conversion cable and all the solders seem to be fine as is the heat wrap on each pin. I'll open up the ecu tomorrow and take a picture

[dorikin]

Follow these steps:

http://img824.imageshack.us/img824/9092/tdct.jpg

http://img84.imageshack.us/img84/9826/tdc2d.jpg

[ECU-MAN]

a photo of the inside of the ECU would be good.

[Egxris]

Was at a wreckers today and got a new b18c2 ecu for $40 plugged it in still getting the check light so it's not the ecu. unfortunately no stock dizzys to grab

[Egxris]

Tried resetting the ecu and running the new dizzy, car went into limp mode??? Reset and Retro fitted the ignitor and rota button into my original dizzy just to see if this worked went into limp mode, fixed some wires and reset the ecu. took it for a drive came back everything was fine until i turned the car off and back on again.check light turned back on. Annoying as when this light is on vtec doesnt work...

Found a Yellow/Black wire that was cut on the engine loom near the ecu. resoldered that (some earth)
Also found 1 wire not soldered anymore on the harness resoldered this but still the light came on?? Giving me the shits lol.

Cars running but check lights coming on. Im guessing the dizzy's TDC is fuked as it takes alittle extra cranking for it to start <-pointing to tdc problem.

Next thing im going to do is check the TDC sensor wires to make sure theyre soldered both ends. Orange/Blue, White/Blue
Try my other new distributor - hopefully doesnt go into limp mode as well now that ive resoldered the harness.
try another ecu OBD1 this time if the above doesnt work.

[ECU-MAN]

Im pretty sure I have mentioned already to you but here it goes again

I dont belive you have a distributor issue, sounds like a wiring problem, or ECU problem. It is very unlikely you have two dizzy's with TDC issues.

you have to perform a continuity test from the dizzy back to the ECU pin ( not conversion harness ) for 8 wires TDC CYP CKP P and G

I can test your ECU and harness free of charge if you cover postage cost's if you really get stuck.

[Egxris]

Tried a new ecu and it still does it so its not the ecu thats at fault. Am i correct in assuming when they wired this they would have had to run new wires to the the distributor to detect the extra sensors the OBDI ecu does not have in it so it would be these that would be faulty. i then will double check the solder joins on the harness that corrospond to these wires once checked.

I'll do this when i get to the shop tonight. i will also bring down the spare Dizzy and try that out again (after i check/fix the wires).

[Egxris]

thanks again for your patience.

i'll go through your testing guide and see how i go tonight

http://www.ozhonda.com/forum/showthread.php?67779-DIY-PGMFI-Diagnostics-Code-8-TDC

i'll double check their wiring to make sure everythings good and swap in the new dizzy. Fingers crossed this is fixed tonight.


Do you know why it would go into limp mode with a different dizzy installed??

[Egxris]

So i spent about 4 hours+ resoldering the harness for it to still not work :( . Im going to swap back in the original OEM Dizzy to see what happens but not optomistic. Getting tired of limp mode.

- ECU - Swapped - Rulled out
- OBD1 - OBD2 ECU Harness - Resoldered and Heatshrinked - Rulled out.
- New Dizzy installed - New ECT - 4/9 - Visual check looks fine. Had a replacment Dizzy under warranty same error codes
- Old Dizzy - ECT - 8

there are some wires that have been wired in (im guessing for the OBD2 conversion to use a OBD2 Dizzy) which look to be ok, But i will check these wires out tonight. I'll then will also do a check on continuety etc as per the service manual pdf.

21492

[ECU-MAN]

this is why I say you need the right tools.


how can you diagnose a problem like this without a scope. once you are 100% sure your wiring is OK, you need to see the waveform from the Dizzy at the correct pin on the ECU in respect to ground.

is it there ?
is it clean ?
is it a rising edge ?
is it a falling edge ?


if your original ECU connectors are OBDIIa then try a OBDIIa ECU and see if you get any codes. totally isolate your harness and OBDI ECU

[Egxris]

Yeh dont have a scope. so atm thats not an option so i'll try everything else i can in the mean time. Ie check wiring and rull out anything else, ie, harness, ecu, dizzy.

Ecu i swapped as i now have 2 B18C2 ecu's same thing happens on both ecu's so its not that
Harness, desoldered and resoldered all connectors. So its not that as its still there.
Swapped in 3 different Dizzy's, 2 the same after market and 1 OEM. 2 after market ones both come up with the same problem- limp mode then eventually throw up a 4/9 error code. OEM Dizzy works, but throws up intermitant error code 8.

Last thing to do is trace wiring from dizzy to harness and make sure its ok check continuety etc. I'm also going to add an extra earth strap to the engine as 1 doesnt seem good enough...

Going to also buy a OBDI ecu on the weekend if the above doesnt help so i can test the loom. All else fails i'll need an autoelec to have a look at the problem....

[Egxris]

So. the new dizzy's both give me code 4 and code 9. the old dizzy gives me a code 8.

the new dizzys both go into limp mode (obviously because of the code 4-9 being important). i pull out the new dizzy put the old one in. the car runs fine. then the check light comes on for code 8.

ive checked the wiring back to the ecu (visually) and everything seems to be fine (i even cut and resoldered 3 wires running back to the ecu.

Can someone tell me what these wires are for? (the blue ones?) 1 wire is wired into my Apex'i Neo (via the purple wire).

21535

[Egxris]

Started the car with a OBD1 B18C2 ECU and it threw up the TDC error code 8.

So its not the ecu and its not the harness.

Also ran a continuety test and this came up fine. no broken link to the ecu either.

Just trying to find an exact same TD-86U Dizzy to swap in to test, if its that im ordering a brand new one from Japan...

It looks like the TD-84U dizzy doesnt want to work on my car, only likes the TD-86U OEM one...Anybody got one i can borrow for 20mins?

[ECU-MAN]

you need to view the pattern of the generated signals from the Dizzy on a scope to find out why you keep getting dizzy related codes.

when you performed your continuity test was the ECU connectors disconnected ? did you check both before and after the harness ? did the wires go to the correct location on the ECU connector, did you test for continuity between the sensors and ground ( test for shorts )

[Egxris]

Yeh no shorts, i tested from the plug at the dizzy to the Orange/Blue wire on the grey plug (not the harness) with everything unplugged. i also checked the harness end to end.

Used this pinout for reference and it was the same

http://www.b18c5eg.com/obd1.jpg

[ECU-MAN]

since all your tests have not found the fault, it comes down to Scope time.

[Egxris]

Going to see if i can borrow the exact same "working" b18c2 TD86U dizzy first then will go the scope :(

[Egxris]

So. I finally got around to swapping in another working TD86U Type R OBDII dizzy, check light is now gone and the car is now working fine.....