Torqbyte Tech Blog

Torqbyte CM5 Water Methanol Safety Features

Torqbyte CM5 and Torqbyte CM5-LT can be configured in many different ways to provide a safety mechanism for almost any water methanol injection set-up.

The most dangerous situation in a water methanol injection (WMI) system is the one where the water meth delivery cuts out under high boost. Over the years, many approaches have been attempted to detect and react to system faults. These approaches included using in-tank float level sensors, measuring pump current to estimate the fluid flow rate, and using in-line flow sensors.

However, unless the WMI controller is sophisticated enough to have an output that can be used to trigger a dump of the excess boost pressure whenever a WMI fault is detected, all that a crude WMI controller could do is alert the driver through some kind of a visual (e.g. LED) or audible (e.g. buzzer) indicator, so that he/she can let off the gas and hope the ECU is able to take the necessary steps to save the engine from detonation damage.

CM5 can be configured to detect system faults using any of the above-mentioned approaches and it also has two General Purpose Outputs (GPOs) that can be used to signal a fault condition to the ECU or to an Electronic Boost Controller (EBC) so the excess boost can get dropped to the wastegate spring level. The CM5 can itself be used as a PID-based EBC. In this case, its ability to drop the boost to safe levels is even more straightforward because it is in control of the boost solenoid and can dump all excess boost directly whenever a WMI fault is detected.

In this blog we will look at three safety approaches that CM5 supports to detect and prevent WMI-related system problems.

Safety Approach 1: Pump Current Monitoring

One of the features that sets CM5 apart from other typical WMI controllers is the user-configurable pump current monitoring. Unlike some of the other WMI controllers that attempt to do the impossible and find a relationship between the water meth flow rate and the pump current, the CM5 only looks at the pump current to address the following conditions:

Condition 1: Is the pump drawing more current than it should be? If it is, this could mean that the line between the pump and the nozzle is blocked, or that an anti-siphon solenoid is stuck in the closed position, or that the pump is seized or corroded by moisture and road salt in set-ups where the pump is exposed to the elements. A condition when the pump is drawing more current than expected is called an overcurrent fault.

Condition 2: Is the pump drawing less current than it should be? If it is, this could mean that the pump has run out of fluid because the tank is empty or the line between the tank and the pump is blocked. It could also indicate that the line between the pump and the nozzle has popped off and fluid is being spilled. A condition when the pump is drawing less current than expected is called an undercurrent fault.

A pump that is pushing fluid through a typical WMI system will draw current that should always fall between some nominal low level, shown as (B) below, and some nominal high current level, shown as (A) below, while the system is functioning as expected. One of the parameters that directly affects the pump current is duty. Clearly when the pump duty is 0% the current will also be 0 A, so there is no point checking for an undercurrent condition when the duty is too low. This duty figure, below which there is little use checking the pump current is shown as (C) below. This value depends on the pump model, diameter of the water meth lines, nozzle, etc. Each of these three points must be determined experimentally for each user's given set-up.


One way to experimentally determine these three numbers is by using the Live View and Output Duty Overrides features of the TorqTune software. By using these tools, the user can command the pump to a certain duty and watch the pump current in the live view to see how that value changes when the pump is full, empty, running through a nozzle, pumping into a blocked line, etc. Clearly you should take steps to avoid any engine damage (like hydrolocking) when performing these tests.

Once the (A), (B) and (C) values for the Main Output Limits or for the AUX Output Limits are known they can be entered into TorqTune via the Settings tab as shown below.

The Time delay field controls how much time between a fault being detected and action being taken will be allowed. Each 100 "loops" to about 4 milliseconds (i.e. 0.004 seconds).

Generally for signalling a fault to an ECU or an external EBC a value of either 0% (OFF) or 100% (ON) should be used to override one of the two low power General Purpose Outputs (GPOs) located at I/O Connector Pin 17 (GPO1) or Pin 18 (GPO2).

Using TorqTune, the CM5 can be configured to set the duty of one of its GPOs in reaction to an overcurrent or undercurrent output fault. This is done via the drop down menus on GPO1 and GPO2 control tabs. In this example let's assume that we want GPO1 to turn on or go to 100% duty (i.e. pull its output to ground) whenever an overcurrent or undercurrent fault is detected on the Main output. To do this we would go to the GPO1 Control tab and select ON when MAIN faulted, OFF otherwise from the GPO1 control drop down menu.

Now whenever an overcurrent or undercurrent fault was detected on the Main output, GPO1 will turn ON (i.e. go to 100% duty) and trigger the ECU or an external EBC to react. 

Although it doesn't have anything to do Water Methanol Injection safety, it's worthwhile mentioning what happens in the Hard Current Limit Zone shown in RED above. CM5's high power outputs are rated for 20A each while CM5-LT's outputs are rated for 10A each. Operating the unit with pumps that exceed these current ratings will eventually cause the unit to shut down the overloaded output. How fast or how slow the overloaded output gets shut down will depend on the unit model (i.e. CM5 vs. CM5-LT) and the amount by which the current limit is being exceeded. The graph below shows an approximate relationship between the amount of overloading and the amount of time, in seconds, it will take for the unit to shut down an overloaded output.

Clearly it is undesirable to have either the WMI pump or the fuel pump shut down unexpectedly during regular operation, but this is the only way the unit can protect itself from eventual destruction by an unchecked overload condition. If the unit continued to operate unprotected during an overload, the pump will shut off anyways once the unit is destroyed by the overload condition. So, it is crucial for the user to ensure the pump(s) used will not overload the unit. If more current is required than the CM5-LT or CM5 are able to supply directly, the user could consider slaving a Torqbyte PM3 to the output(s) that requires more current. A Torqbyte PM3 Pump Amplifier can output up to 36A of current. If your set-up requires more than 36A for your fuel or your Water Methanol Pump it's probably worth taking another look at your set-up and seeing if the current approach is really the most optimal.

Safety Approach 2: Fluid Level Monitoring

The most common way to detect WMI trouble is to monitor a float switch that opens or closes based on the level of the fluid in the water meth reservoir. A smart placement of this switch will see it installed so that it reacts not when the the reservoir it totally empty to a point where the pump is starved of fluid, but slightly above that so a low fluid level condition will be flagged while there is still some fluid in the reservoir.

Since the output of a float level switch is essentially a logic signal (i.e. ON or OFF) it can be connected to one of the CM5's General Purpose Inputs (GPIs) located at I/O Connector Pin 7 (GPI1) or Pin 8 (GPI2) as shown:

Then, using TorqTune, the CM5 can be configured to set the duty of one of its outputs to some user entered value. Generally for signalling a fault to an ECU or an external EBC a value of either 0% (OFF) or 100% (ON) should be used to override one of the two low power General Purpose Outputs (GPOs) located at I/O Connector Pin 17 (GPO1) or Pin 18 (GPO2).

In TorqTune this is done via the Settings Tab. In this example let's assume that we want GPO1 to turn on or go to 100% duty (i.e. pull its output to ground) whenever GPI1 is active (i.e. when its being pulled to ground by the float switch). To do this we would focus on the GPI duty table overrides section. First we would select Override GPO1 when high from the GPI1 control drop down menu. Then we would set the Override duty value to 100%.

Now whenever the fluid level in the reservoir is running low and the level switch closes to pull the GPI1 line to ground, GPO1 will turn ON (i.e. go to 100% duty) and trigger the ECU or an external EBC to react. 

Safety Approach 3: Fluid Flow Monitoring

Another way to detect WMI trouble is to use one or two flow sensors which sit in-line between the pump and the engine and/or the pump and the reservoir and generate a 0-5V voltage depending on the flow rate through the sensor.

Since the output of a flow sensor is a voltage ranging from 0-5V it can be connected to one of the CM5's Analog Voltage Inputs located at I/O Connector Pin 13 (AN_A) or Pin 15 (AN_B) as shown:

Then, using TorqTune, the CM5 can be configured to set the duty of one of its outputs to some user entered value. Generally for signalling a fault to an ECU or an external EBC a value of either 0% (OFF) or 100% (ON) should be used to override one of the two low power General Purpose Outputs (GPOs) located at I/O Connector Pin 17 (GPO1) or Pin 18 (GPO2).

In TorqTune this is done via the Settings Tab and the Output tab of the desired GPO. In this example let's assume that we want GPO1 to turn on or go to 100% duty (i.e. pull its output to ground) whenever AN_A drops say 2.5V voltage (assuming that given our flow sensor an output of 2.5V or less represents an unacceptably low water meth flow rate).

To do this we would first focus on the Basic Config section on the Settings tab. First we would set the voltage range limits for the Analog A input. In this example let's set them to 0V (Min) and 5V (Max). 

Then on the GPO1 Table tab we would set the GPO1 control drop down menu selection to OFF above setpoint, ON below it. We would also set the Vertical Axis drop down menu selection to Analog Input A. Finally we would define the set point values. Since we don't want the engine RPM to be ever be be a factor we would simply enter the maximum RPM value in the Engine Speed field. In this example we are using 8000 RPM, which is the same value we used for the Maximum Engine Speed on the Settings tab. We would set the AN A input field to the flow rate sensor output voltage that corresponds to some unacceptably low flow rate. We are using 2.5V in this example, but that value depends entirely on the flow rate sensor you are using.


With these settings flashed to the unit, GPO1 would be OFF (i.e. 0%) whenever the AN A voltage was above 2.5V and would be ON (i.e. 100%) whenever the AN A voltage dropped below 2.5V. As before, GPO1 turning ON (i.e. going to 100%) can be used and trigger the ECU or an external EBC to react accordingly.

Any one of these features can be used individually or two and three can be used at the same time allowing the user to achieve whatever desired level of safety for their Water Methanol Injection set-up.  

Posted by Torq Byter_ on 18 October, 2015 Read more →

Connecting Torqbyte CM5 to an EBC

Torqbyte CM5 is equipped with an advanced safety feature not found on any other water-methanol pump controller.

CM5 monitors the pump current on both of its output channels and is able to alert the user if the pump current drops below or rises above some user-programmable threshold. A fault condition where the pump current drops below a threshold could indicate the pump is out of water methanol fluid. A fault condition where the pump current climbs above a threshold could indicate a blocked water methanol injection line or even a seized pump (a common occurrence with externally mounted Aquatec DDP 5800 water methanol delivery pumps).

So... what can be done with this feature?

CM5's configuration software, TorqTune, allows the user to configure one of the unit's two General Purpose Outputs (GPOs) to either turn ON or turn OFF when a fault is detected on one of the pump outputs. Since these outputs are "pull-to-ground" types, when they turn ON they are connecting whatever goes there to vehicle's ground.

When a fault is detected on one of the two pump outputs, the CM5's front panel FAULT LED flashes on and off, but that is rarely useful since in most installations, the unit it hidden from driver's view.

At the most basic level, a LED or a buzzer could be connected to the particular GPO to alert the driver that a fault has been detected so that he/she may take appropriate action. However, the reaction time delay associated with having a human in the loop may be way too long to avoid serious problems in a possible scenario where the system runs out of water methanol fluid under high-boost.

If the CM5 itself is configured to perform electronic PID boost control, it will automatically dump all the boost pressure when a pump fault is detected. But what it the CM5 is not used for boost control? What can be done in set-ups where a separate Electronic Boost Controller (EBC) is used?

The solution is fairly straightforward.

In this blog post we will consider how to use Torqbyte CM5's advanced safety features with a popular e-Boost2 EBC manufactured by Turbosmart. 


The approach described here can be used with other EBCs that allow their main boost setting to be overridden (or zeroed) by grounding one of its inputs.

e-Boost2 has two optional wires, Green and Orange that can be used to activate up to 4 different boost set points. By default these wires are not connected to anything (i.e. they are left floating) so the e-Boost2 just uses its boost Set Point 1.

However, if the user grounds (i.e. connects to a vehicle ground) the Green wire, e-Boost2 will start using its boost Set Point 2, or if he/she connects the Orange wire to ground, e-Boost2 will start using its boost Set Point 3.

Table below shows what boost Set Point, the e-Boost2 will use based on that the user does with the Green and Orange wires.

Active Boost Set Point Green Wire Orange Wire
Boost Set Point 1 Unconnected (Floating) Unconnected (Floating) 
Boost Set Point 2 Grounded Unconnected (Floating)
Boost Set Point 3 Unconnected (Floating) Grounded
Boost Set Point 4 Grounded Grounded

Obviously, when a water methanol pump fault is detected, the best course of action would be to immediately dump all the boost pressure to protect the engine. To achieve this, what needs to be done is to set the e-Boost2's Boost Set Point 2 or Set Point 3 to 0PSI and connect either the Green or the Orange wire to CM5's GPO1 or GPO2, depending on what else the other GPO may be used for.

In this example, we are assuming that that e-Boost2's Boost Set Point 2 has been set to 0PSI and that the CM5 has been configured in TorqTune to turn on its GPO2 output when a fault is detected on its MAIN Pump Output.

 All that is required then is to splice together the Green Wire on the e-Boost2 to the Green Wire in Position 18 on the CM5's Input/Ouptut connector, which is its GPO2 output.



Posted by Torq Byter_ on 18 October, 2015 Read more →

Upgrading the OEM Wiring for the New High Power Fuel Pump

You've just installed an upgraded in-tank Low Pressure Fuel Pump (LPFP) in your factory fuel sender basket. You have your Torqbyte PM3 pump amplifier or your Torqbyte CM5 ready to power the new pump, but there is a problem:

The OEM wiring harness that plugs into your fuel sender most often uses very thin 16AWG wires that the manufacturer found appropriate for the amount of current drawn by the factory LPFP that comes with the car. The manufacturer should have anticipated that you will need a larger in-tank pump to fuel your out of control boost addiction and should have installed larger 10AWG fuel pump power wires - but they didn't.

Now what? Leaving those thin factory wires in place will create a bottleneck that will, at best, prevent the you from getting the most out of your new pump and quite possibly cause a fire hazard if the new pump draws more current than those 16AWG wires can safely handle causing them to overheat.

What can you do?

You could simply purchase our VAG Plug-n-Play Adapter Harness or make your own DIY PM3 P-n-P Harness or your own DIY CM5 P-n-P Harness, but given access to the right contact removal and crimping tools you could also rework your factory wiring to achieve the same result.

The male connector on top of the fuel sender is molded into the plastic top of the fuel sender assembly so you can't change it. You also can't drill into the fuel sender cover to pass larger diameter wiring into the tank as you'll never be able to make a safe and reliable seal around the wires. This is clearly an _extremely_ bad idea and should never be entertained.

The issue must be addressed at the connector that normally plugs into the fuel sender. To illustrate the proceudre we'll use the VW/Audi connector Part No. 1K0 919 231 that is found on a large number of VAG vehicles.


This is a hybrid 5 position (aka 5-way) connector made for VW by TE Connectivity (aka AMP / Tyco). Positions 1 and 5 supply the power to the fuel pump.

Step 1 - Remove the old wires from the connector housing

Before attempting to remove the contacts, first remove the plastic retainer (aka Terminal Position Assurance or TPA lock). This is a small pink, U-shaped piece of plastic that is snapped into position around the contacts. You can disengage it (which will allow the contacts to be removed later) by using a very small tipped screw driver and gently pushing it out towards the slot in the side of the connector until it clicks once. Don't remove the TPA from the connector housing or you won't be able to re-insert it once the contacts are put back in the housing. It only needs to disengage one click.

Now you'll need a contact removal tool TE Connectivity Part No. 1-1579007-3 available from many online suppliers such as,,,, etc. This tool is shown below.

When you insert it through the front of the connector, this removal tool will simultaneously compress two spring-loaded tangs that hold the connector in the housing and allow you to (gently) pull the wire and contact out from the back. If you don't use the proper tool at this step you will likely damage the contact and probably damage the plastic housing preventing the new contact from locking in.

Step 2 - Install larger wires into Positions 1 and 5

Here you are faced with two options:

Option A: Quicker and cheaper but with some compromises depending on what you are doing.

You can just buy a wiring repair kit from the dealer that comes with the right terminals and pre-crimped 4mm^2 (i.e. 12AWG) wire. The VW/Audi Part No. 000 979 308 E provides you with a single wire with two terminals (one on each end), so all you need is one of these because you can cut it in the middle which will provide two pieces for the two positions you are trying to fill.

The first compromise with this approach is that you are limited to about 25A of peak current by the wire supplied with this kit. If you are using something like a TTRS pump this wiring will be fine, but if you are using something exotic it may not be enough.

The second compromise is that for whatever reason VAG doesn't include integrated pre-crimped silicone wire seals with this kit. Just look at the wires you pulled out in Step 1 and you'll see they each have a silicone wire seal that is "clasped" and held by the metal at the end of contact that you pulled out. However the VAG wire repair kit provides no silicone seal on the wire provided. We are not sure why VAG supplies these kits without the integrated wire seal, other than that there are many housings these can go into and each housing may require a different seal, but the manufacturer TE Connectivity states clearly that you should never add the seal onto the wire after it's been crimped. Anyways, if you chose to do it the VAG-way you can ask the dealer for a couple of wire seals and and slide them on from the cut wire side after you cut the provided wire in half. DO NOT slide the seal over the crimped metal contact as you will stretch and probably tear the seal.

Option B: MUCH more expensive but without any compromises, this option is probably the right way to go for dealers or shops that might perform this work on a regular basis.

Positions 1 and 5 accept terminals from the AMP MCP6.3/4.8K FLATCONTACT family. These contacts are shown below.

The manufacturer product family drawing can be downloaded HERE.

You can see in that drawing that there are two contacts that will fit into this housing AND accept a single wire sealing system (i.e.a silicone seal).

If using 12AWG wiring you'll need Qty 2 Contacts, TE Part No. 1241416 or 1241417
If using 10AWG wiring you'll need Qty 2 Contacts, TE Part No. 1241418 or 1241419

In either case you'll need a couple of silicone wire seals for the 8.5mm cavity (which is the cavity size of the VW connector at Positions 1 and 5) TE Part No. 1719043-1, but since these TE seals are rarely available anywhere, you can use a Delphi (GM) Part No. 15324990 instead.

To crimp the contacts and the seals onto your wiring you'll need the TE manual crimper Part No. 539635-1 shown below.

However this crimper is supplied blank and you'll need to purchase the crimping dies separately.

For the 12AWG wiring using contacts TE Part No. 1241416 or 1241417, you'll need crimping dies TE Part No. 539956-2.

For the 10AWG wiring using contacts TE Part No. 1241418 or 1241419, you'll need crimping dies TE Part No. 3-1579021-7.

You can get all these parts from your favorite online supplier such as,,,,, etc.

The manufacturer crimping specification can be downloaded HERE.

Once you've crimped the wires and seals as per above specification, insert the contacts into positions 1 and 5 tug on them gently to make sure they are locked in place. Make sure the seal is firmly in the cavity and then re-install the pink plastic TPA lock by applying pressure on it through the slot in the side of the connector until it snaps/clicks into place.

That's all - now you have an adequate wiring connection from the PM3 to the top of the fuel sender. We'll address the upgraded wiring on the inside of the tank in the next blog.

Posted by Torq Byter_ on 28 June, 2015 Read more →

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