Excellent. In that case, do not buy another tool yet. Your Snap-on TPMS5 already has the OBD functions we were looking for.

And I found a feature in the TPMS5 manual that is almost tailor-made for diagnosing your exact problem: Verify IDs/DTC Codes.

Update the TPMS5 first over Wi-Fi:

1. Connect the TPMS5 to Wi-Fi.
2. Main Menu → Update.
3. Install any available update.
4. Let the tool restart.

Snap-on specifically recommends keeping its vehicle coverage current. TPMS5 User Manual

Then select:

RAM → ProMaster City → 2019 → appropriate 5-tire configuration

Now, instead of going directly to Relearn:

Main Menu → Special Functions → Verify IDs/DTC Codes

This is the important part.

According to Snap-on, it performs three separate tests:

1. Triggers each physical TPMS sensor and records its transmitted ID.
2. Connects through OBD-II and reads the sensor IDs currently stored inside the vehicle.
3. Reads the TPMS system's diagnostic trouble codes.

Snap-on specifically says that if the physical sensor IDs and stored ECU IDs don't match, a relearn is necessary. Snap-on TPMS5 manual — Verify IDs/DTC Codes

This is exactly the information we're missing.

Have your TPMS5's OBD-II cable ready. It was originally included with the TPMS5.

Start Verify IDs/DTC Codes.

Trigger all five sensors as prompted, including the spare if the selected configuration requests it.

You'll get information such as:

Then the TPMS5 will advance to DTC Codes.

At that point:

1. Engine OFF.
2. Connect the OBD-II cable to the TPMS5.
3. Connect the other end to the van's OBD-II diagnostic connector.
4. Turn ignition to ON/RUN but do not start the engine.
5. Tap OK.

The TPMS5 should communicate with the vehicle.

It will first show any TPMS DTCs.

Write those codes down or photograph the screen before doing anything else.

Then continue to Verify IDs.

The TPMS5 should compare the IDs it just received from the tires against the IDs stored in the vehicle.

Because one sensor was replaced, I'm particularly suspicious of this situation:

If that's what it shows, we've essentially solved the mystery.

The new sensor is perfectly good, but the vehicle hasn't successfully replaced the old sensor ID in its learned TPMS data.

Battery disconnect wouldn't correct that.

If the IDs don't match:

TPMS → Relearn

The TPMS5 manual says the Relearn function determines the vehicle-specific method and, when applicable, allows an OBD-II relearn using the supplied cable. Snap-on also explicitly advertises the TPMS5 as being capable of writing sensor values to the ECU through OBD-II. Snap-on TPMS5 product information

Follow exactly what the TPMS5 displays after selecting:

RAM → ProMaster City → 2019

If it offers something similar to:

OBDII Relearn

choose that rather than the automatic/drive relearn.

Trigger the sensors in exactly the order requested. Then connect the OBD cable when instructed and allow the TPMS5 to write the IDs.

Because all five of your physical sensors:

• respond to the TPMS5;
• report reasonable pressure;
• report reasonable temperature;
• have unique IDs;
• report good batteries;

I would not use Replace, Create, Copy, etc. yet.

First use Verify IDs/DTC Codes.

That test may tell us precisely what is wrong.

In fact, I'd suggest that you don't even perform the relearn immediately after the test. Give me:

1. The exact DTC code(s) the TPMS5 reports.
2. Whether Verify IDs says all IDs match.
3. If they don't match, which tire doesn't match and the two IDs it shows.

With those three pieces of information, I can research the specific DTC and tell you whether we should perform an OBD relearn or whether the problem is actually on the ProMaster City's TPMS receiver/module side.