What the TMS-4 is
The TMS-4 is a tire pressure monitoring system built to talk to a Haltech ECU. Four wireless sensors report pressure and temperature to a receiver, and the receiver passes that data to the ECU over the Haltech CAN bus. From there it behaves like any other ECU channel. You can log it, display it, and use it to raise trouble codes.
It comes in two kits that differ only in the sensors:
| Internal kit (HT-011600) | External kit (HT-011601) | |
|---|---|---|
| Sensor location | Inside the tire, replacing the valve | Screws onto the existing valve stem |
| Install effort | Tires off the wheels, then rebalance | Minutes per wheel, no tire work |
| Sealing | IP67 | IP69 |
| Battery | CR2023, not replaceable, around 3 years on average | CR1632, user-replaceable, typically 1-2 years |
| Extras in the box | Warning stickers | Four anti-theft lock nuts and a wrench for them |
| Best for | Track cars and anything fast, where you want the sensor protected | Street cars, or trying the system without a tire shop visit |
Both kits include the receiver, a TE MCON to DTM-4 CAN cable, mounting nuts and washers, and a quick start guide.
Specs worth knowing
- Works with Haltech ECUs in both NSP (Nexus) and ESP (Elite).
- Pressure range from 0 to 116 psi (0 to 800 kPa) on both sensor types.
- Sensors work from -40°F to 257°F (-40°C to 125°C).
- The receiver works from -40°F to 185°F (-40°C to 85°C) and is sealed to IP67.
- The receiver uses a 6-pin TE MCON connector; the supplied adaptor turns that into a standard 4-pin DTM-4 for the Haltech CAN bus.
Installation
Receiver
Mount the receiver with the supplied hardware, as high up in the car as practical. Radio signals from the wheels get through glass and plastic far better than through steel, so a spot high in the cabin generally picks up all four corners more reliably than one low under the dash. Plug it into the Haltech CAN bus with the supplied cable. When it powers up you'll hear it beep, which is a handy first check.
External sensors
- Take off the valve cap and set the tire to the pressure you want.
- Run an anti-theft lock nut onto the valve stem.
- Match each sensor to its corner using the position sticker, and screw it on.
- Snug the lock nut up against the sensor with the supplied wrench.
- Spray the stem with soapy water and watch for bubbles.
Internal sensors
- Let the air out and dismount the tire from the wheel.
- Remove the old valve.
- Fit the sensor for that corner, going by its position sticker.
- Remount the tire carefully. The sensor is easy to hit with the machine's bead tool, so tell your tire shop it's there.
- Inflate and have the wheel dynamically balanced.
Turning it on in the software
- Nexus (NSP): go to Connections > CAN > Haltech CAN System and enable Tyre Monitoring (TMS-4 Enable). Once the ECU sees the receiver on the bus it should show up in the menu tree, and you can enable it there too.
- Elite (ESP): open Main Setup (F4), go to Devices, and enable Tyre Monitoring (TMS-4 Enable). It then appears alongside your other CAN devices.
Note that the software spells it "tyre", as Haltech is an Australian company. When you search for channels, "tyre", "tire" and "wheel" all find them.
Sensors, wheels and channels
Out of the box, each sensor is assigned to the corner printed on its sticker. You can re-assign any sensor to any wheel in the setup menu, so rotating tires or swapping a spare wheel doesn't mean moving sensors around. You can also switch off a corner you don't want to monitor.
The channels you get fall into two groups. Per tire channels (pressure, temperature, sensor voltage) follow the wheel position. Per sensor channels (pressure, temperature, battery voltage) follow the physical sensor, wherever it's fitted. There's also a single Air Leak Detected channel covering all four tires, and Recommended Tyre Pressure values, which are only there for logging and dash display and don't drive any alarms.
Setting up alarms
All the TMS-4 trouble codes are optional and are enabled in the TMS-4 setup menu. Two rules apply to all of them: a sensor that isn't assigned to a wheel can't raise a code, and codes are named for the wheel, not the sensor. So if the sensor labeled rear left is fitted to the front left and loses air, the code you'll see is for the front left tire.
| Alarm | What triggers it | Our advice |
|---|---|---|
| Pressure High / Low | Pressure outside the min/max you set for that axle for 3 seconds or more | Set front and rear separately. Leave enough room for normal hot-vs-cold pressure change, or you'll get nuisance warnings on track |
| Temperature High | Any sensor at or above your maximum temperature | Useful on track days to catch a dragging brake or an overworked tire |
| Air Leak Detected | On by default. Either the sensor's own leak flag, or a pressure drop you define occurring within 5 seconds | The user-defined drop catches fast leaks well. Start with the sensor logic and tighten it if you want earlier warning |
| Sensor Battery Voltage Low | Any sensor battery below 2.3 V | Worth enabling so a dead battery is never mistaken for a flat tire |
| Sensor Signal Loss | An active sensor stops reporting | Needs a working vehicle speed input, because sensors sleep when the car is parked and the ECU must know they should be awake |
Batteries and maintenance
External sensors use a CR1632 coin cell you can change yourself: remove the sensor from the stem, unscrew its cover, push the old cell out, press the new one in, and refit. Recheck for leaks afterward. Internal sensors use a sealed CR2023 that can't be replaced. At around three years of average life, they usually outlast the tire they're in, so plan to replace the sensor when an aging one is due for a new tire anyway.
Keep an eye on the per-sensor battery voltage channels in your logs. A cell that sags over a few months tells you it's time before the low-voltage code does.
Troubleshooting
| Symptom | Usually |
|---|---|
| No beep at key-on | No power at the CAN connector, or the adaptor cable isn't fully seated |
| Receiver shows but a wheel reads nothing | Sensor hasn't woken yet (drive the car or change the pressure), the corner is disabled, or the receiver is mounted low and shielded |
| Warning names the wrong wheel | Sensor assignment doesn't match where the sensors are actually fitted |
| Signal loss codes that never clear | Vehicle speed isn't set up, so the ECU can't tell when sensors should be awake |
TMS-4 FAQ
Can I show tire pressures on my Haltech dash?
Yes. The TMS-4 channels are normal ECU channels, so a compatible Haltech dash can display them alongside the rest of your data.
Internal or external sensors?
External for convenience and street use; internal for anything that sees high speeds or curbs, where a sensor on the valve stem is exposed. Not sure? Ask us.
