Launch control issue

This section is dedicated to discussion of DTA engine control units such as the DTA E48 EXP, P8 Pro, DTA S40, S60, S80, and S100, as well as all things ECU related.
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John Loudon
Posts: 29
Joined: Mon Jul 20, 2020 3:47 am
ECU Model: S100 Pro

Launch control issue

Post by John Loudon »

Can anyone offer me some advice about an S100 ECU please? I am using launch control on pin 4 of the 4 key plug of the ECU but when I press the launch button the rad fan pulses. The rad fan is fed by a standard 4 pin relay via pin 4 (aux 2) on the 3 key ECU plug and goes to the negative terminal on the relay. Now you might think that I have the pins wired to the wrong ECU plugs as aux 2 and launch are both pins 4 but I havent. Is there anything in the DTA software on the Aux 2 page or the rad fan operation page that may be causing this? I did not build the loom but it was done professionally and worked on the previous car. I added the rad fan subloom myself. Thanks guys
SMR
Posts: 137
Joined: Tue Jan 16, 2018 9:38 am
ECU Model: S100 Pro
Distributor: DTA
Location: Aberdeen

Re: Launch control issue

Post by SMR »

The rad fan/aux2 grounds the relay, so the other side of the "trigger" (terminal 85 or 86) needs fed with 12v. Is that how you've got it wired?
John Loudon
Posts: 29
Joined: Mon Jul 20, 2020 3:47 am
ECU Model: S100 Pro

Re: Launch control issue

Post by John Loudon »

Hi yes that's how I have it. I'm wondering if a wiring fault with the launch and traction potentiometer could cause it? They have black, pink and yellow wires. Can someone confirm which each is please? I have pink as +12v, black as ground and yellow as %. Thanks
JON-TEC-RALLYE
Posts: 38
Joined: Sat Jul 30, 2011 4:35 pm
ECU Model: S100 Pro
Distributor: JON-TEC-RALLYE
Firmware Version: 89
Location: Canary-Island

Re: Launch control issue

Post by JON-TEC-RALLYE »

Good morning, connect your pc to dta, so you say there may be a temporary short circuit when you press the button, and the ecu warns by making the fan work, a large red screen appears on the pc screen indicating that there is a short- circuit. to the connector -B- pin 4 there will be a button normally, to pin -10- Ana 1 / Traction Cut% / Launch RPM that must be the potentiometer or a multi-position switch.
DTA--MoTec--Link--Ecumaster--HONDATA
Antral
Posts: 194
Joined: Mon Aug 01, 2011 8:20 am

Re: Launch control issue

Post by Antral »

Launch is by a momentary switch signal and ground. Launch pot is by a pot so 3 wires 5v, signal & ground. the pink wire is probably 5v.
I think you have a ground problem somewhere from when you moved the loom to a different application.
John Loudon
Posts: 29
Joined: Mon Jul 20, 2020 3:47 am
ECU Model: S100 Pro

Re: Launch control issue

Post by John Loudon »

If rad fan control is selected in Engine Config > Sequential control does the Ana2 /Aux 2 function have to be set to active in Other Map Settings or does it take care of itself?
stevieturbo
Posts: 3577
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Launch control issue

Post by stevieturbo »

If Aux2 function is not checked, then the output side of Ana2 really should not operate.

I guess if it is checked...it may override the fan function ?

The Ana/Aux really need to be divorced.
John Loudon
Posts: 29
Joined: Mon Jul 20, 2020 3:47 am
ECU Model: S100 Pro

Re: Launch control issue

Post by John Loudon »

Update - I've found the fault and rectified it. I had a pair if pins in a 4 way Deutsch DTM plug the opposite way round, one of which was an earth. Swapped to correct way round and all working perfectly now Thanks for all the tips. The car was mapped the day before Christmas eve and behaved perfectly once running
SMR
Posts: 137
Joined: Tue Jan 16, 2018 9:38 am
ECU Model: S100 Pro
Distributor: DTA
Location: Aberdeen

Re: Launch control issue

Post by SMR »

Good to hear it's fixed!
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