I was wondering if anybody could tell me what the red wire does that runs from the instrument cluster (speedo) to the VSS. I know the white wire is signal out but I have a feeling the red is either power to the VSS from the cluster or visa versa. The reason I ask is because the auto goes into limp home mode with the cluster disconnected and my autometer speedo will not work when connected to either the red or white (although I get movement from the pointer when connected to the white but this will happen even when stationary). Any help would be appreciated.

EA Series 1 - ECU
PIN wire colour Description
1 yellow Keep Alive Memory Power
3 white Vehicle Speed Sensor
5 red/green Key Power - B+ when igntion is switched on
6 yellow Power Steering Pressure Switch
7 greeen/yellow Engine Coolant Temperature sensor
10 blue Air Con Clutch Relay
16 black Ingition Ground
17 white/black Self test output
21 grey/white Idle Speed Control Device
22 brown/green Fuel Pump Relay or circuit
25 yellow/red Air Charge Temp
26 orange/black Sensor Volatge Ref
29 green/blue Heated Exhaust Gas Oxygen sensor
30 orange/black Neutral Drive switch
31 yellow/blue Canister Purge enable output
34 green/yellow Serial Data Output Port (Link) TRIP Comp
36 yellow/green Spark Output from the EEC IV
37 red Vehicle power B+
40 black/green Vehicle ground battery negative (-)
45 blue/yellow Manifold Absolute Pressure
46 black/white Zero ref for most sensors
47 green/black Throttle Position Sensor Voltage
48 white/red Self Test Input
49 grey/blue Heated Exhaust Gas Oxygen sensor GND
56 brown Profile Ignition Pulse
57 red Vehicle power B+
58 dark brown bank 1
59 green bank 2
60 black/green Vehicle ground battery negative (-)



4 Speed Auto Trans Computer (TCU)
PIN wire colour Description Notes
1 Blue/Yellow Temp Sensor (input)
2 Orange Diagnostics (input)
4 Blue Air Con status (input)
5 Blue/Orange Temp Sensor ground
6 Pink Ignition system, engine speed signal (input) loom pink/blue behind cluster
7 Green Solinoid 5 return (input)
8 White/Red Diagnostics (ground)
9 Blue/White Throttle Position (ground)
10 Violet/White Shift Lever Position (ground)
11 Green/Yellow Solinoid 4 (input)
12 Green/Black Solinoid 1 (output)
13 Yellow/Red Solinoid 6 (output)
14 Green Mode indicator dash light (output) Negative (-)
15 Yellow/Black Battery Positive (power)
16 Blue/Red Throttle Position (input)
17 Violet Shift lever (input)
18 Red Econ/Preformance Mode switch (input) Negative (-)
19 White Shaft SApeed Sensor (input)
20 Green/Blue Diagnostics (output)
21 Black Ground
25 Blue/Green Throttle position sensor reference 5v (power)
26 Green/Red Solinoid 3 (input)
27 Green/White Solinoid 2 (input)
28 Yellow/Green Solinoid 7 (output)
29 Yellow Solinid 5 (output)
30 Red/Green Ignition switch (power)

I believe the sensor has three wires:

Red +12V
White Signal
Black Ground

The signal is a 50% duty cycle, 5V peak, square wave. Make sure this is the signal format your Speedo needs. It might have a switch to change pulse type.

As for limp home mode, I am pretty sure your dash sends the speed signal to the ECU, so if the dash is disconnected there is no chance of the ECU getting the speed signal. I'll check this.

So do I assume the 12v is supplied to the sensor from the cluster? That would make sense. And I do know for a fact the white wire tee's off and goes to the ecu (so basicallt the ecu and speedo get their signal from the same source).

Yep the red wire is 12v to the sensor from the cluster. Also make sure you got the right white wire, as when I did my car there were two white wires that carried the VSS signal to/from the cluster. For my car that has the two connector setup for the digital speedo it was pin number 5 on the cluster connector that carried the signal from the VSS to the speedo.

Thanks for your input guys. Ill let you know how I go.

Thanks for your input guys. I ran 12v to the red wire and bingo, speedo works as autometer intended it to. However the auto is still in limp home mode so thats got me stuffed. Any thoughts?

That will be in limp mode because the ECU is not getting the speed signal. It gets that from the dash. You might need to loop out of the speedo into the trans controller.

Are you sure cause the wiring diagram show the wire as teeing off and going to the speedo and the ecm independantly? I'm not saying your wrong cause what your saying makes sense but maybe the manual is wrong.