Tach access

rb136 · 02-18-2007

I'm installing a data acquisition system in my SLK55 and am having trouble finding a place to hook up an input for the tach in the DA system. I've tried tapping into one of the LV leads on one of the coils but the signal is unstable. It reads right most of the time but becoms erratic under acceleration. Does anyone know if there is a remote tach ouput in the ECU or any other place I can get a 12V pulsed signal that is proportional to engine speed?

DansSlk · 02-19-2007

Not sure of any good places to tap off of the top of my head sorry.

No separate output on the ECU its all CANBUS

rb136 · 02-21-2007

Figured it out. You have to use shielded wire and route it away from the other coils and fuel injectors. The shielding grounds through the DA system and into the lighter plug where it gets it's power. Signal is clean now.

02-18-2007	#1 (permalink)
rb136 SLK World Member Join Date: Feb 2007 Location: Baytown, Texas Vehicle: SLK55 Other Toys: 05 G55 AMG Posts: 77 Country: Thanks: 3 Thanked 30 Times in 6 Posts	Tach access I'm installing a data acquisition system in my SLK55 and am having trouble finding a place to hook up an input for the tach in the DA system. I've tried tapping into one of the LV leads on one of the coils but the signal is unstable. It reads right most of the time but becoms erratic under acceleration. Does anyone know if there is a remote tach ouput in the ECU or any other place I can get a 12V pulsed signal that is proportional to engine speed?

02-19-2007	#2 (permalink)
DansSlk Dude Join Date: Jun 2006 Location: Wales Vehicle: 05 B55S (Brabus 6.1 S) Posts: 6,752 Country: Thanks: 96 Thanked 221 Times in 173 Posts	Not sure of any good places to tap off of the top of my head sorry. No separate output on the ECU its all CANBUS __________________ One thing you will learn with German cars - If it's simple it ain't happening.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Access into lighting unit	Lizard	General Modifications R171	4	01-14-2008 06:58 PM
Easiest Access to the Horn	SLKDawg	General Modifications R171	5	11-20-2007 11:09 AM
Anyone worked out how to access the engineering mode on newer comand systems?	aquascape	SLK R171 General Discussion	1	10-21-2007 08:16 PM
Best access to ACC	devlinmc	General Modifications R171	19	03-01-2007 10:40 AM

02-21-2007	#3 (permalink)
rb136 SLK World Member Join Date: Feb 2007 Location: Baytown, Texas Vehicle: SLK55 Other Toys: 05 G55 AMG Posts: 77 Country: Thanks: 3 Thanked 30 Times in 6 Posts	Figured it out. You have to use shielded wire and route it away from the other coils and fuel injectors. The shielding grounds through the DA system and into the lighter plug where it gets it's power. Signal is clean now.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)