NCM-2 & VRM-1 Troubleshooting

Symptom or Issue

Possible Cause & Action

1. The windshield mount will not stick to windshield.

Follow the steps in  "Mounting the NCM-2 Nitrous Control Module" on page 6.  Try to mount the suction cup to the flattest possible area on the windshield where it will not obstruct your vision.

2. The SYSTEM STATUS indicator is flashing.

This indicates the NCM-2 has detected a fault. Refer to "System Fault Codes and Status Indicator" on page 18 of the Installation Instructions and Operating Guide.

3. The nitrous will not activate when I reach full throttle.

The NCM-2 will activate the nitrous when the Throttle Angle meets or exceeds the current Throttle Position Sensor trigger point when the nitrous is enabled (Indicator next to ENABLE button). From the factory, the NCM-2 is programmed not to engage nitrous unless the user has recorded a valid TPS Trigger point. Perform the steps listed in "Pre-Functional Check & Programming the TPS Trigger Point" on page 11 and "Setting the Throttle Position Trigger Point" on page 16 of the Installation Instructions and Operating Guide.

4. The display will not dim when I turn my headlamps on.

The connection to the Park Lamps (BROWN wire) is not connected or it is connected to an invalid signal wire. Follow the steps in "Connecting to Park Lamps" on page 9 of the Installation Instructions and Operating Guide.

5. The display dims, then goes bright when I turn my directionals on.

The BROWN wire on the NCM-2 is connected to the turn signal wire rather than the park lamp wire. Follow the steps in "Connecting to the Park Lamps" on page 9 of the Installation Instructions and Operating Guide.

6. I cannot locate the Throttle Position Sensor (TPS).

Turn the key off. Have an assistant actuate the throttle while looking under the hood for the throttle linkage to move. The TPS should be located on the opposite side of the throttle body.

7. I cannot locate the Throttle Position Sensor Output Signal wire.

Ensure you are actually trying to connect to the Throttle Position Sensor (TPS) and not another type of sensor on the vehicle.  Some vehicles use a Manifold Absolute Pressure (MAP) sensor that could be mounted on or near the throttle body. This can be easily confused for the TPS. 

9. My Throttle Position Sensor (TPS) has more than 3 wires on it.

Some earlier vehicles (mid 80’s imports) have Throttle Position Sensors that also include a closed throttle switch. As long as you can locate a wire that increase as the throttle angle increases you can connect the PURPLE wire to that wire.

If your vehicle is a late model vehicle, it may be equipped with a drive-by-wire system. Contact VENOVUS Engineering for technical assistance.

10. My Throttle Position Sensor (TPS) goes directly to 5 or 12 volts as soon as I open the throttle.

Some mid/late 80’s imports, particularly Toyota, Mazda, Isuzu and Nissan vehicles use a throttle switch rather than a sensor. The NCM-2 will not work on these vehicles. Contact VENOVUS Engineering tech support for assistance if you experience this issue.

11. The fuse on the NCM-2 harness is blown or blows when the nitrous is activated.

You may have connected the GRAY or LIGHT BLUE wire from the NCM-2 module directly to the nitrous solenoids. The NCM-2 is not capable of driving the nitrous solenoids directly (they draw several amps). You will need to install relays or a VENOVUS' VRM-1 module between the NCM-2 and nitrous relays. Refer to  "Solenoid Connections Using Venovus VRM-1" on page 13 for more information. If after you have connected the relays the nitrous does not active, but the NITROUS ACTIVE indicator is on you may have damaged the NCM-2. Contact VENOVUS Engineering tech support for assistance.

This is caused by electrical interference and is a result of the way the PURPLE wire is routed. Ensure the PURPLE wire is routed in a way that avoids; ignition wires, distributor cap, ignition coils, coil packs, alternator, window wiper motor etc.