Signal Wire for Aftermarket Tachometer on 06 LSJ

GoblinGuyZ

GoblinGuyZ

Well-Known Member
Hi all in the process of planning and preparing to run an AEM CD digital display on my Goblin using their Can Bus Module and aftermarket sensors. I would like to use this to replace the current cluster. It has GPS Speedo but need a signal for the Tachometer / RPM reading. Anyone used and aftermarket tachometer? If so wondering what wire you used to get the signal. TIA
 
Goblinfanclub1234

Goblinfanclub1234

Well-Known Member
I would think that a 2005 ss is the same as 2006. from the cobalt ss forums...

2005: tach signal is at cylinder #1 ignition coil, brown wire with white stripe (ignition coil driver #1 from PCM)
 
GoblinGuyZ

GoblinGuyZ

Well-Known Member
No it can’t use the obd2 port. They do make a obd adapter but it doesn’t work on the LSJ or most cars before 08. They make a 22 channel can bus module which is what I will be using and the signal has to go into that
 
Ross

Ross

Goblin Guru
HP Tuners is using the CAN bus. The high speed GMLAN is exposed on the OBD2 port. This is what was later called the CAN bus.
Not sure why there adapter doesn't work, but if you need access to the CAN bus, you can get it from the OBD2 port. (Pin 6 and pin 14 on the OBDii port.)
 
GoblinGuyZ

GoblinGuyZ

Well-Known Member
Ross said:
HP Tuners is using the CAN bus. The high speed GMLAN is exposed on the OBD2 port. This is what was later called the CAN bus.
Not sure why there adapter doesn't work, but if you need access to the CAN bus, you can get it from the OBD2 port. (Pin 6 and pin 14 on the OBDii port.)
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Yes I got all that but unfortunately it's not compatible with most aftermarket OBD readers out there, I tried two different universal OBD2 gauges, work on all my other vehicles but not that, I got the OBD adapter for the same AEM display and same thing. Maybe it's an older protocol hence why most of these gauges and devices only guarantee from '08 and up
 
Ross

Ross

Goblin Guru
Oh. Now I understand. There are quite a few OBD2 protocols.
I think my 2006 LSJ is ISO 15765-4 CAN (29 bit ID, 500 kbaud)
Yusta posted some documentation about it here.
 
GoblinGuyZ

GoblinGuyZ

Well-Known Member
So I'm finally doing this and have all the sensors, fuel level and GPS speedo working well but the Tachometer I can't get to work for anything. I've tried every single wire off the coils and the #26 pin wire on the second connector on the ECU which is supposed to be the engine speed signal wire but I notice the pinout I have says it's supposed to be white but mine is dark gray with a white stripe but I tried it anyway as I assumed the position was more important than the color. Any ideas? Pulling my hair out on this last signal and can't drive or clean it all up until I get it sorted.
 
GoblinGuyZ

GoblinGuyZ

Well-Known Member
So after a bit more digging I think I found the correct ECU Pinouts for my engine (attached). I notice none of the connectors mention Engine Speed at all now and what I was trying to tap into was apparently the Cam sensor. So it seems I need to get a signal off the coils themselves but nothing is working so back to the drawing board. I wondered if I need a tach adapter but wouldve thought the CD dash would be advanced enough to pickup any signal.
 

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Goblinfanclub1234

Goblinfanclub1234

Well-Known Member
could it be a problem with the configuration settings in the AEM dash itself? not mapping to the correct input on the dash or something? can you test the tach gauge on the AEM dash with a different vehicle to confirm it is working.

are you using the 6 channel CAN sensor module??
 
GoblinGuyZ

GoblinGuyZ

Well-Known Member
Goblinfanclub1234 said:
could it be a problem with the configuration settings in the AEM dash itself? not mapping to the correct input on the dash or something? can you test the tach gauge on the AEM dash with a different vehicle to confirm it is working.
Click to expand...
That’s what I thought but tried everything. I think I found a manual work around by inputting a range for the Hz vs rpm that is within about 3% accuracy compared to the stock dash so may just use that and call it a day.
 
Goblinfanclub1234

Goblinfanclub1234

Well-Known Member
oh so you are able to get a signal and the gauge is moving? that's a win

the manual recommends negative terminal on coils, but also not to do that for high output systems. not sure if the cobalt is considered high output.
 

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GoblinGuyZ

GoblinGuyZ

Well-Known Member
Goblinfanclub1234 said:
oh so you are able to get a signal and the gauge is moving? that's a win

the manual recommends negative terminal on coils, but also not to do that for high output systems. not sure if the cobalt is considered high output.
Click to expand...
Yeah I saw that but have no idea which wire is the tachometer output wire in the dash. I tried the various pins that plug into the back of the oem dash as well but wasn’t getting any signals from them.
 
GoblinGuyZ

GoblinGuyZ

Well-Known Member
GoblinGuyZ said:
Yeah I saw that but have no idea which wire is the tachometer output wire in the dash. I tried the various pins that plug into the back of the oem dash as well but wasn’t getting any signals from them.
Click to expand...
I
Goblinfanclub1234 said:
oh so you are able to get a signal and the gauge is moving? that's a win

the manual recommends negative terminal on coils, but also not to do that for high output systems. not sure if the cobalt is considered high output.
Click to expand...
The high output systems are usually not stock setup but aftermarket special coils
 
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