stand Alone PCM wire question(s)
Thread Starter
Safety Car
Joined: Aug 2013
Posts: 3,962
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stand Alone PCM wire question(s)
the first one for starters Is the VSS (vehicle Speed Sensor) ..
on my T56 drag car (soon) do I really NEED to Imput any speed information to the Transmission sensor for any good reason?
Reason I ask and hope I dont need is because I got a Great looking ENGINE wire harness to convert the stock pcm to Stand alone ANd I am Awaiting the response if the VSS plug on this harness is an input or output... If its an Input then I would just plug it in to one wheel sensor to send speed info to PCM ,. then I wouldnt plug anything into the t56 ...
I eliminated the BCM so I dont have any speed info coming in to the pcm... if the new harness is An output Ill be scratching MY head for a while how to input speed into the Factory ECU/pcm
thanks in advance for any Input
pun intended
on my T56 drag car (soon) do I really NEED to Imput any speed information to the Transmission sensor for any good reason?
Reason I ask and hope I dont need is because I got a Great looking ENGINE wire harness to convert the stock pcm to Stand alone ANd I am Awaiting the response if the VSS plug on this harness is an input or output... If its an Input then I would just plug it in to one wheel sensor to send speed info to PCM ,. then I wouldnt plug anything into the t56 ...
I eliminated the BCM so I dont have any speed info coming in to the pcm... if the new harness is An output Ill be scratching MY head for a while how to input speed into the Factory ECU/pcm
thanks in advance for any Input
pun intended
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
The VEHICLE SPEED SENSOR is on the DIFFERENTIAL. You can NOT use a wheel speed sensor for vehicle speed.
There are ZERO speed sensor wires on the T56....
Only wiring should be on the T56 is:
Reverse Lock Out Solenoid
CAGS 1st to 4th shift solenoid
&
On a ZO6 there is a Trans Oil Temp Sensor inside the Oil Fill Port instead of a pipe plug.
VSS Differential:
(top of picture, passengers side of the case)
There are ZERO speed sensor wires on the T56....
Only wiring should be on the T56 is:
Reverse Lock Out Solenoid
CAGS 1st to 4th shift solenoid
&
On a ZO6 there is a Trans Oil Temp Sensor inside the Oil Fill Port instead of a pipe plug.
VSS Differential:
(top of picture, passengers side of the case)
Thread Starter
Safety Car
Joined: Aug 2013
Posts: 3,962
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THanks.. I have 0 wires in the car and no fuse boxes .. So just wondering where I can get the speed to input into the pcm ... you say not wheel sensor directly? or does the Diff VSS calculate speed as it turns and sends it to PCM>?
Thread Starter
Safety Car
Joined: Aug 2013
Posts: 3,962
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next 2 questions which is the HOT wire for stock key ignition and Starter --- ?
2nd which is the HOT wire from the wire pump at pumps?
thanks in ADVANCE
2nd which is the HOT wire from the wire pump at pumps?
thanks in ADVANCE
Last edited by Gxpz06; Mar 17, 2016 at 04:36 PM. Reason: big THANKS
Race Director
Joined: Apr 2007
Posts: 11,152
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From: South Western Ontario
I'm not sure if you got the VSS question answered, but the sensor is in the diff (the output) and it connects directly to the PCM (the input). The harness should have a VSS wire you just connect to the diff sensor. If it's a stand-alone harness for an engine and transmission bolted together then you'll have to lengthen the wires.
The BCM doesn't provide a speed signal to the PCM, nor do the wheel sensors.
The BCM doesn't provide a speed signal to the PCM, nor do the wheel sensors.
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Thread Starter
Safety Car
Joined: Aug 2013
Posts: 3,962
Likes: 64
I'm not sure if you got the VSS question answered, but the sensor is in the diff (the output) and it connects directly to the PCM (the input). The harness should have a VSS wire you just connect to the diff sensor. If it's a stand-alone harness for an engine and transmission bolted together then you'll have to lengthen the wires.
The BCM doesn't provide a speed signal to the PCM, nor do the wheel sensors.
The BCM doesn't provide a speed signal to the PCM, nor do the wheel sensors.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
This is a 1999 Schematic. The fuse references will be different for other later model years:
Thread Starter
Safety Car
Joined: Aug 2013
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thanks bill ... by that schematic It looks like I would run the 2 red to 12v battery ,. the yellow to starter ("crank" at fuse) and the brown to Ignition off Pcm ..
Ill give it a shot and let know the outcome in few days..
lastly need to know which is power wire from the rear wires coming off the fuel pumps.... ?!
thanks in advance
Ill give it a shot and let know the outcome in few days..
lastly need to know which is power wire from the rear wires coming off the fuel pumps.... ?!
thanks in advance
Thread Starter
Safety Car
Joined: Aug 2013
Posts: 3,962
Likes: 64
thanks bill ... by that schematic It looks like I would run the 2 red to 12v battery ,. the yellow to starter ("crank" at fuse) and the brown to Ignition off Pcm ..
Ill give it a shot and let know the outcome in few days..
lastly need to know which is power wire from the rear wires coming off the fuel pumps.... ?!
thanks in advance
Ill give it a shot and let know the outcome in few days..
lastly need to know which is power wire from the rear wires coming off the fuel pumps.... ?!
thanks in advance
