18x signal missing

Holden/Delco Tuning. ALDL, OBD 1.5. Circa 1989 to 2004.
Post Reply
User avatar
Rhysk94
Posts: 45
Joined: Sun Mar 15, 2020 7:25 pm
cars: VE SS-V
VY V6 Turbo “Ecojet”
FG XR6 Turbo
VY V6 Stocker Farm Hack
VY V6 Turbo Manual Drift Hack
VY L67 Calais
N80 Toyota Hilux
VX Stocker Farm Hack
FG XR6 Turbo
Location: Perth
Contact:

18x signal missing

Post by Rhysk94 »

Hey guys,

My VY drift hack has stopped starting.
Once or twice DTC47 has come up.
I have changed CAS over to 3 spare's and then bought a new one.
Have changed coils and DFI over to my 2 other spares.
Coils still spark, Injectors show 12v at them to ground, but across terminals only shows 7ish volts and doesn't show it pulsing to ground (stays constant the entire time).
Have changed over 3 ecu's (flashed no vats to each one)
It shows that the 3x signal is present and that 18x isnt on both Tunerpro and Envyous Customs software.
It also shows rpm when cranking
Anyone come across this and or know what it could be, I feel as if I have checked over everything it could possibly be but there are always people
out there who know more or have experienced more so here I am hahaa

Cheers in advance,
-Rhys
-RKGarage
immortality
Posts: 3416
Joined: Thu Apr 09, 2009 12:31 pm
cars: VH, VN, VS, VX

Re: 18x signal missing

Post by immortality »

Check the wiring loom.

If you are getting spark than the DFI and CAS are working correctly but the signal must be going missing after the DFI module.
User avatar
Rhysk94
Posts: 45
Joined: Sun Mar 15, 2020 7:25 pm
cars: VE SS-V
VY V6 Turbo “Ecojet”
FG XR6 Turbo
VY V6 Stocker Farm Hack
VY V6 Turbo Manual Drift Hack
VY L67 Calais
N80 Toyota Hilux
VX Stocker Farm Hack
FG XR6 Turbo
Location: Perth
Contact:

Re: 18x signal missing

Post by Rhysk94 »

cheers immortality, i have already stripped the entire loom back and found no faults.
had a look again today and this time had dtc42 popup, seems to be no fix online for this found sadly
immortality
Posts: 3416
Joined: Thu Apr 09, 2009 12:31 pm
cars: VH, VN, VS, VX

Re: 18x signal missing

Post by immortality »

No idea sorry. Do you have a scope of some sort to see if you are getting the x18 signal out of the DFI module?

Do you have a wiring diagram? I only have VT/VX but it should be the same as VY around the DFI module and associated wiring.
Attachments
05b.pdf
VX Powertrain Module Wiring Diagram
(312.18 KiB) Downloaded 136 times
User avatar
Rhysk94
Posts: 45
Joined: Sun Mar 15, 2020 7:25 pm
cars: VE SS-V
VY V6 Turbo “Ecojet”
FG XR6 Turbo
VY V6 Stocker Farm Hack
VY V6 Turbo Manual Drift Hack
VY L67 Calais
N80 Toyota Hilux
VX Stocker Farm Hack
FG XR6 Turbo
Location: Perth
Contact:

Re: 18x signal missing

Post by Rhysk94 »

yeah have already scoped every single forum and post ever about these issues haha, I don't have scope but may have to invest in one.
tried the led trick as well and that didnt work on both 3x and 18x, yet I know the ecu is seeing the 3x signal :think:
User avatar
Rhysk94
Posts: 45
Joined: Sun Mar 15, 2020 7:25 pm
cars: VE SS-V
VY V6 Turbo “Ecojet”
FG XR6 Turbo
VY V6 Stocker Farm Hack
VY V6 Turbo Manual Drift Hack
VY L67 Calais
N80 Toyota Hilux
VX Stocker Farm Hack
FG XR6 Turbo
Location: Perth
Contact:

Re: 18x signal missing

Post by Rhysk94 »

Update for anyone else that comes across this issue.
It was the cam sensor. (Which showed as working fine in turnerpro and envyous customs softwares).
Replaced it and it fired right up and never had an issue.
immortality
Posts: 3416
Joined: Thu Apr 09, 2009 12:31 pm
cars: VH, VN, VS, VX

Re: 18x signal missing

Post by immortality »

Thanks for coming back with a solution.

Looking at the wiring diagram the cam and crank sensors share the same +12 and ground wires, maybe something inside the cam sensor was screwing up the voltage to the crank sensor and causing a poor signal?
User avatar
vlad01
Posts: 7780
Joined: Mon Oct 08, 2012 6:41 pm
cars: VP I S
VP I executive
VP II executive
VP II executive #2
VR II executive
Location: Kyneton, Vic

Re: 18x signal missing

Post by vlad01 »

Yes, maybe the cam sensor was shorting/pulling the 12v down to ground and the 18x wasn't reaching threshold due to low voltage.
I'm the director of VSH (Vlad's Spec Holden), because HSV were doing it ass about.
Last_Carton
Posts: 16
Joined: Tue May 22, 2018 9:50 pm
cars: VT Sedan Acclaim II 3.8L V6

Re: 18x signal missing

Post by Last_Carton »

hey guys,

I actually had the same issue on my VT turned out to be a corroded and broken wiring for main PCM power on the chassis side of the 3 plugs on drives die engine bay. might be worth a look? what happens is water runs down the windscreen onto the cowling and down in behind those plugs.
User avatar
Rhysk94
Posts: 45
Joined: Sun Mar 15, 2020 7:25 pm
cars: VE SS-V
VY V6 Turbo “Ecojet”
FG XR6 Turbo
VY V6 Stocker Farm Hack
VY V6 Turbo Manual Drift Hack
VY L67 Calais
N80 Toyota Hilux
VX Stocker Farm Hack
FG XR6 Turbo
Location: Perth
Contact:

Re: 18x signal missing

Post by Rhysk94 »

vlad01 wrote:Yes, maybe the cam sensor was shorting/pulling the 12v down to ground and the 18x wasn't reaching threshold due to low voltage.
Just saw this. that is a very good point! I did measure with a multimetre and it got the correct voltage. also a multimeter on the 18x input at the dfi and it sweeped the correct voltage as well when it picked up the teeth.
Post Reply