Hey guys, I am having a drama trying to get my tacho to work with my LS1B Ecu. I'm running an autometer tacho and have wired the car and engine from scratch.. It is an LS2 using an LS1B ecu and throttle cable. OS 01290005 custom COS5. I have connected the tacho output wire from the ECU to the gauge and set the gauge for 4cyl operation etc. I have also tried using a few different resistors for a pullup signal etc. Nothing is working and I am getting P0654 code.

From what I have read, the factory cluster is supposed to provided a voltage on that wire to the ECU and the ecu then switches the ground from there. This is what I have tried to achieve with the pullup resistors but still no luck. Does anyone know how much voltage the ECU is expecting to receive? I have access to an oscilloscope and it looks as though the ECU is not switching the earth. Tach pulses High is 3 and Low is 3 in the tune. Have tried internal pullup setting On and Off. I have freezeframe data:

Engine Speed Output Circuit
Subsystem Category Of DTC P
Fuel System Bank-1 OL
Fuel System Bank-2 OL
Calculated Load Value 0.4 %
Engine Coolant Temperature 62 °C 144 °F
Short Term Fuel Trim - Bank 1 0.0 %
Long Term Fuel Trim - Bank 1 0.0 %
Short Term Fuel Trim - Bank 2 0.0 %
Long Term Fuel Trim - Bank 2 0.0 %
Intake Manifold Absolute Pressure 68.0 kPa 9.9 PSI
Engine RPM 1320 RPM
Vehicle Speed Sensor 0 KMH 0 MPH
Air Flow Rate From Mass Air Flow Sensor 2.14 Grams/s 0.28 Lbs/Min
Absolute Throttle Position 0.0 %
Unused -
Exhaust Gas Recirculation Valve Sensor Voltage 0.0 V
Fuel Tank Pressure Sensor Voltage 0.0 V
Exhaust Gas Recirculation Valve Position 0.0 %
Engine Coolant Temperature At Startup 62 °C 144 °F
Desired Idle Speed 825 RPM
Desired Exhaust Gas Recirculation Valve Position 0.0 %
Barometric Pressure 99.6 kPa 14.5 PSI
Commanded Air Fuel Ratio B - LS2 12.9 :1
Engine Run Time 0 Seconds
Misfire Current Status 255 Counts
Mileage Since Last Code Cleared 0 Km 0 Miles
Odometer When Last Code Set Was Cleared 0 Km 0 Miles
Freeze Frame Counter 0 Counts
Freeze Frame Pass Counter 0 Counts
Freeze Frame Not Run Counter 0 Counts
Injector Base Pulse Width Bank 1 2.960 ms
Injector Base Pulse Width Bank 2 2.960 ms
ETC Average Pedal Position 0 Counts
ETC Indicated Throttle Position 0 %
ETC Desired Throttle Position 0 %
Accelerator Pedal Position 0 %
Pressure Switch indicates INVALID No
Transmission Output Speed 0 RPM
Current Gear 1
Subsystem Category Of DTC P

Is the 'Misfire Current Status' something to worry about? That is the only thing I can see which may set the code..

Any help is appreciated.
Thanks