Reading Stock TPMS Data Externally

[ZR2]

Hey guys,

For the ease of deflation using APEX valves, i know there are specific after market TPMS that provides an external tiny device/monitor to read the tire pressures. I want to keep my stock TPMS, but have something that reads the tire pressures. After some digging,
there isn’t a simple “external dash screen” that wirelessly reads the OEM TPMS sensors directly over RF all the time, but rather they require their own
valve-cap sensors.

The practical approach i found was to use an OBD reader that is capable to read live TPMS data and has an iphone app that i can see the readings when deflating. Not sure if you guys have done something similar.

My questions are:
- Which OBD tool you recommend that can provide live TPMS data and has a phone application. I have the BlueDriver OBD, but TPMS data, however, lives in proprietary GM networks (Body Control Module / Tire Pressure Module) and uses manufacturer-specific PIDs that BlueDriver doesn’t read or broadcast in real time.

- Do you recommend an OBD extension to use 2 ports as i have the power steps connected and want to connect an OBD reader too.

- Can i install secondary TPMS sensors in addition to the stock oness.

Sorry for the long message and appreciate your support

 

[ZR2]

Bringing it up

 

[ZR2]

Here’s what I’m going for FYI, I decided to use the OBDLink MX+ Bluetooth OBD-II reader. It’s fully compatible with iPhone, supports GM’s SW-CAN/GMLAN protocols, and can pull enhanced factory data including live TPMS readings, transmission temps, and other module info. I’m pairing it with the AMP Research OBD Pass-Through Harness (P/N 76404-01A) so my PowerSteps can stay plugged into the truck’s OBD port at the same time. The pass-through isolates and conditions the CAN-High/Low lines, maintaining proper 120 Ω termination and avoiding signal collisions. A regular Y-splitter won’t work because both devices would try to act as masters on the CAN bus, which can cause corrupted frames, disconnects, or even disable the steps temporarily.