Hang Tight PSC 2.0 Instructions

First and foremost, thank you for purchasing the PSC! It’s been tested in the harshest conditions, and we’re extremely grateful for your trust in the product. We’re confident the PSC will make your driving experience more reliable, and more enjoyable.

If you prefer a PDF version, you can download that here.

1.0 - Connections

The PSC has 2 connectors, a 6 pin and a 3 pin. Both are Amphenol/Deutsch DTM series. These can be purchased on the Hang Tight website here: https://hangtight.io/collections/amphenol-connectors/products/amphenol-atm-female-connector.

The pinout for the 6 pin is as follows:

1. 12V switched power. When this pin is powered the PSC will turn on and turn the EPAS unit on
2. Chassis ground
3. PWM input, for control from a device such as an aftermarket ECU. 
4. 5V supply for potentiometer
5. Signal input from potentiometer 
6. Sensor ground for potentiometer

The 3 pin connector connects to the EPAS unit only. Hang Tight offers premade harnesses to make install easy, but if you wish to do your own wiring the pin out is as follows;

1. CAN High
2. CAN Low
3. 12V switched power to pump

2.0 - Mounting Instructions

Included with every PSC is 2 M6 bolts, 2 nuts, 2 washers and 2 riv-nuts (¼-20 hardware may also be used if that is preferred).

See the dimensions at the end of this guide for mounting hole locations. The PSC may be mounted face up, or on its side from either the top or bottom.

The 3D printed cases are rated for ‘x’ C* temperatures, keep distance from heat sources if you’re installing the PSC in an engine bay. The PSC is fully potted and sealed to IP68 rating, resulting in a water resistant product.

3.0 - Setup

Now that the PSC is wired and mounted, and you’ve installed your EPAS unit, simply power up the PSC on and you’re set! The PSC automatically detects which EPAS unit it is connected to and starts controlling it. Adjust the assist level with either a potentiometer or the PWM input.

It’s that easy.

PWM input is low side (to ground) input and accepts a frequency of 100-400 Hz. 

5% DC will give 0% EPAS assist and 95% DC will give 100% EPAS assist. 

It is important to have the ECU or controlling device powered on at the same time or before the PSC if using this method, if the PSC does not see a PWM input between 5%to 95% in the first ‘5’ seconds after startup it will default to potentiometer input.

The PSC is looking for a 0-5V signal, so either a trim pot, rotary or linear potentiometer or even resistors in a MUX configuration could be used to control it. Potentiometers should be 0-500 ohms, these are available for purchase from Hang Tight. 

A trim pot such as AEM 30-2056 may also be used. 

If you are switching between inputs, the PSC’s power will need to be cycled. It’s also important that the PSC’s 12V output to the pump be used to enable the pump as many have specific timed startup sequences. 

PSC has a roughly ½ a second boot up time, each EPAS unit is slightly different with its turn on time, but if PSC is wired on with ignition it should give enough time to crank the engine over and get it running before the EPAS becomes a load on the battery.

4.0 - Operation

If no control input connected the PSC will default to 0% assist, same as if the potentiometer input was all the way down.

5.0 - Troubleshooting

Red LED - Error state

No power - check for 12V and ground at 6 pin connector

If there are any issues around pump limits or performance, please contact us for assistance.

6.0 - EPAS unit specific tips and tricks

Electric power steering has some great advantages over traditional mechanical belt driven pumps. Steering systems are designed to make good pressure at lower rpm when you’re driving around parking lots at low speeds. But once you’re racing or at speed and the engine is turning that pump really fast, it’s creating a lot of heat in the fluid. You also want less assist at higher speeds, which helps for steering feedback.

Off road vehicles usually want more steering assist when at low speeds rock crawling, where engine speed is probably low and inconsistent as you’re maneuvering over obstacles, engine speed determines pump flow and if the engine speed is inconsistent so is the pump.

Drift cars also present a unique use case, they need a lot of assist in drift but not so much that it numbs the steering feel. Their engines also rev very high and stay there, and then when the run is over they are at a standstill with little to no air flow across the car. Heat management is critical to consistent steering feel, and consistent steering is what driver’s are after.

Electric power steering can solve all the problems above, offering driver controllable assist levels and consistency due to the pump not being linked to the engine’s speed. These systems also run much cooler then mechanical pump systems as they are not over pumping fluid.
Assist level can be adjusted for vehicle speed, steering angle, rate of steering angle change, temperature, etc. Using the PSC’s PWM input and your aftermarket ECU of choice you can make your control strategy as simple or as complex as you like. Just know we don’t recommend using GPS based speed due to its potential lack of consistency.

A potentiometer or trim pot can also be used, they can be in reach of the driver or located near the controller. In conversions or cases where changes in assist are not frequent, usually the system only needs to be adjusted right after install. Competition vehicles may want to adjust more often.

Electric Power Steering Systems do require a healthy electrical system. Your alternator and battery need to be in good health. If your alternator is below 100A in output it's worth considering upgrading. You should also ensure that your power and ground connections are tight and paint free. Cables could be upgraded to a larger size.

These pumps can draw up to 100A for a brief time, though they will mostly draw much lower than that.

EPAS units main power can be wired to constant power, they are only “on” when the PSC enables it.

For the case of the electro-hydraulic EPAS units, using grommets that rubber isolate the pump from vibration will ensure it lasts long. Special note should be paid to mounting orientation and angle, you want to make sure the pump’s inlet always has air-free fluid to it. The pickup should be at the low point in the fluid.
A cooler may not be necessary depending on your application, but never hurts to have.


A filter is also a good idea, metal debris from worn steering racks/boxes or dirty fluid can destroy a pump.

It is important to use pressure hoses rated for up to 2000 psi. The system will not always operate at that high a pressure, but it can spike that high. Teflon or crimped hydraulic lines are a must.

For the case of column mount EPAS units, special attention should be paid to the mounting of them under the dash. The mounting will need to be adequately strong to counteract the torque created by the motor. If the mount flexes it could cause weak steering assist, or break causing damage.

Modifying steering column components also needs to be done with care. Components need to be strong enough to take the additional torque that is applied through them.

These units can generate some heat, keeping some air gap around the unit under the dash will promote some cooling, in some cases a fan may be needed. Not all dashboards have the room to fit these types.

These units are not as strong as the electro hydraulic systems, consider how much force and for how long the vehicle will be used.

7.0 - Hang Tight PSC Pump Support

Dodge

These are the most powerful, fastest reacting pumps supported by PSC. They are so strong that we have limited the software to prevent damage to steering racks. Please contact us if your specific install needs different pump limits.

Great for off road, drift cars and heavy track use. Does just fine at lower assist levels for conversions as well.

Pinout:

1. CAN H
2. 12V
3.  CAN L

Remote reservoir units

• 2011-13 Dodge Durango, 3.6L V6
• 2014-15 Dodge Durango, 3.6L V6
• 2011-13 Jeep Grand Cherokee, 3.6L V6
• 2018-20 Jeep Wrangler*** Support TBD

Integral reservoir units

• 2011-15 Dodge Charger, 3.6L V8
• 2011-15 Dodge Challenger, 3.6L V8
• 2011-18 Chrysler 300, 3.6L V8

Amp draw can be up to 80A for short bursts, 8 AWG recommended, 100A fuse

Pressure fitting is specific hydraulic type, straight and 90 versions available from Hangtight.io

Reservoirs can be swapped from integral and remote (Dorman 603-939)

If sourcing these pumps from a wrecker be careful of vehicles with major front end collision damage. The SUV’s have them mounted low down on the front subframe in front of the engine. The cars have them mounted in the front fender passenger side below the windshield washer fluid bottle.

Uses Mopar Power Steering Fluid +4 or Mopar ATF +4 (PN 05013457AA)

Mazda 

Medium strength pump. Great for classic conversions and lighter drift cars.

Pinout:

1 - n/c

2 - CAN L

3 - n/c

4 - CAN H

5 - n/c

6 - 12V ignition

2 connector pumps, integral reservoir. 

• 2010-13 Mazda 3
• 2010-13 Mazda 5

80 A fuse, 8 awg recommended 

Metric fitting adapter M12x1.5mm??

These pumps are located under the passenger headlight. Can be damaged in a front end collision, if water gets into the case it will cause the electronics inside to fail. Years listed are the 2 connector models. We strongly recommend against using the 3 connector variant as they are known to be unreliable (older then 2010 models)

Uses Dexron 3 ATF

Toyota Electric Power Steering Column

Yaris, Corolla and Pruis all use them, making them a very common column unit. Great for classic conversions, lighter track cars or autoX cars that have short lap times. Will create heat during prolonged track use.

There is a shunt resistor that will turn off the unit when the temperature gets too high from the current draw. This can be bypassed for extreme uses, but user beware.

Pinout 

1 - CAN H

2 -

3 - 

4 -

5 - 

6 - IGN 12V

7 - CAN L

8 - 

9 - 

10 - 

11 - 

12 - 

2004-09 Prius/Corolla/Yaris - White connector

2010-15 Prius/Corolla/Yaris - Black connector

Note polarity of white and black connectors is reversed.

50A fuse - 8 AWG

Volvo

These pumps are medium strength, similar to Mazda. They can operate in limp mode without the CAN connected, but using a PSC you can control them same as the other units supported.

M12x1.5mm to -6AN

2004-13 S30, S60

2011-13 S60, C30, C70, V50, XC60

80A fuse, 8 AWG wire