To drive the 1.6L fuel pump
Since the stock ECU does not trigger the fuel pump, but the AFM does, we need a circuit to be able to prime and drive it properly. We back-feed 12v into the fuel pump relay to make it happen. You must remove ST_SIG fuse else you will short out the circuit.
For this circuit you can use one of the tip125s you do not typically utilize: q12 or q9.
Connect the banded end of D4 to VTEC_Out_to_MS.
Connect the VTEC_Out to your harness going to 1C.
You can use s19 for your 12v source.
You MUST remove ST_Sig fuse under the hood or you will burn up the transistor!!!
Here's how I did mine:
Fan / Relay Control Mod
The easiest way to do this is using an existing circuit built in the MS, the Middle LED circuit. Since we don't install Q4, we can use that transistor to drive the circuit. The transistor that currently is in place is too weak to drive the relay.
Swap Q7 for Q4
Run the flat side of the middle LED out to your harness
Under the software you'll enable the middle LED circuit to use Output 4 and then turn output to drive the fan control.
Another method iIf you need something to trigger to ground at a certain temp or RPM, pick up the fan mod kit…
This is a simple circuit that you can build into the PROTO area. You can use it for fans or any other ground you need to trigger.
Top Leg: Goes to ground
Middle Leg: To JS0 through a 1K resistor
Bottom leg: To your harness; install the banded end of the diode to D9
If JS0 was used as your output, simple fill out the ON and OFF temperature on the bottom of this section.
If you need to control more than fans, the different circuits can be made to go to four other outputs:
output1: JS2 (used for boost control)
output2: JS3 - generally used to switch relays on/off that control various items, e.g. Cooling fan, Electric Power Steering Pumps, VVT valves, etc.
output3: Pin15 of the uF - This output has the option for a delayed off. So once it has trigger the output will only turn off after the time delay.
output4: D15 - generally used to switch relays on/off that control various items, e.g. Cooling fan, Electric Power Steering Pumps, VVT valves, etc.
Boost Control Mod
MS has a built in Boost Control feature. With this mod you can drive a boost control solenoid.
Mount the FET on the heatsink. Place the supplied insulator under the FET else it will cause the circuit to fail.
Top Leg: Goes to ground
Middle Leg: To harness (usally through the spare IAC outputs)
Bottom Leg: To JS2 through a 100ohm resistor
Jump the top and bottom leg with the 10K resistor
Solder the banded end of your diode to S12, and run it to the middle leg of the FET.
Boost Control Solenoid:
Purchase this solenoid to control your boost. Buy two 1/8" fittings to accept your vacuum lines.
Run your boost source off the turbo into the port labeled EXH. Run a line from the port labeled OUT to your wastegate.
Run one of the wires to a constant 12v source (most use the blue connector near the driver headlight). Run the other wire to your harness and back into the middle leg of the FET.
Make sure the JS2 function is changed from output 1 to Boost Control:
Your parameters should look like this:
Use the Duty Cycle Table 1 to control the solenoid, the higher the DC% the more boost:
Idle Control Mod
- Mount your TIP120 to the heatsink. Place the supplied insulator under the FET.
- Run the wires to Q4 as shown above
- Do not install Q20 or D8
- Jump R39 with a wire
- Solder the banded end of your diode to S12, and run it to the middle leg of the FET.
For 1990-93 cars, other years may be different and the wrong settings can damage your IAC valve
The wiring for the MS is mainly external. Inside the MS itself, you simple need to run a wire from the harness input to JS10 (labeled as JP1 above).
Follow the instructions that come with the KnocksenseMS for more detailed instructions on setting up knock sensing.