# Direct or Indirect TPMS?



## fatmike409 (Jan 29, 2013)

Wife bought a 2016 Cruze, LT with RS package. The car has TPMS equipped, she has had the car since June, and no issues. We had winter tires from her old cruze so today i popped them on. The winer tires from her old cruze didn't have TPMS so i expected to see a warning light and message when starting up the car after putting the winter tires on her new cruze. However, no light came on (other than the TPMS light that comes on briefly at start up and goes out as part of the vehicle startup) and decided to take the car for a drive as i always do to ensure the tires feel good etc. In my 10 minute drive... the TPMS light didn't come on the dash and i was able to view the TPMS readings in the DIC. I would have assumed if the system was direct it would have given an error at the startup and also given an error when checking the TPMS readings in the DIC.... is this system setup with and indirect system run through the ABS and does not have sensors in the wheels? After my 10 minute drive and turning the car off and on a few times i received no warnings or lights.

I spent the last week prepping my wife she was going to have to deal with a warning light on her dash for the next several months as I wasn't shelling out for tpms sensors on 5 year old winter tires... next year when we need to replace we'll get the sensors but i can get one more winter out of them. Looks like that may have been all for nothing lol.

If anyone can let me know that would be great... I just am surprised is all.

Thanks!


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## UpstateNYBill (Jan 14, 2012)

Were the summer tires still in the car when you test drove it? If so, it is still reading those tpms sensors.


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## fatmike409 (Jan 29, 2013)

UpstateNYBill said:


> Were the summer tires still in the car when you test drove it? If so, it is still reading those tpms sensors.


No, I had already put them away in the garage.


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## Robby (Mar 1, 2013)

fatmike409 said:


> Wife bought a 2016 Cruze, LT with RS package. The car has TPMS equipped, she has had the car since June, and no issues. We had winter tires from her old cruze so today i popped them on. The winer tires from her old cruze didn't have TPMS so i expected to see a warning light and message when starting up the car after putting the winter tires on her new cruze. However, no light came on (other than the TPMS light that comes on briefly at start up and goes out as part of the vehicle startup) and decided to take the car for a drive as i always do to ensure the tires feel good etc. In my 10 minute drive... the TPMS light didn't come on the dash and i was able to view the TPMS readings in the DIC. I would have assumed if the system was direct it would have given an error at the startup and also given an error when checking the TPMS readings in the DIC.... is this system setup with and indirect system run through the ABS and does not have sensors in the wheels? After my 10 minute drive and turning the car off and on a few times i received no warnings or lights.
> 
> I spent the last week prepping my wife she was going to have to deal with a warning light on her dash for the next several months as I wasn't shelling out for tpms sensors on 5 year old winter tires... next year when we need to replace we'll get the sensors but i can get one more winter out of them. Looks like that may have been all for nothing lol.
> 
> ...


The 2016 and earlier, as opposed to the 2016.5 are direct tpms.........that means, I don't know if the 2016.5 are direct or not.
So, assuming you have the 2016 first generation, the reason you don't have a warning (yet) is because the tpms transceiver has not called for a status check from the sensors.
When it does, you'll have the warning.

If a sensor (at the tire valve) sees a pressure drop below threshold, it sends a signal, 'waking up' the transceiver which then sets a warning light.......since there was no pressure change, everything is still 'asleep'.

Like I said though, the transceiver will eventually do a 'health check', expecting a signal from each, coded sensor.......obviously, it won't get a response.....then you'll have the light.

Something that has made me wonder "why" from time to time is the original GM system was indeed, indirect and was abs based.....this for the 2001 model year.
At the same time, German cars introduced the direct systems........GM adopted this system around 2005/2006.
Now, the German cars and several of the Asian manufacturers (specifically Mazda) have abandoned the direct systems and are going indirect.

I prefer the indirect from a simplicity standpoint, but it won't allow different tire circumference or dissimilar front to rear tire pressure unless the abs computer is programmed for the varience.

Rob


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## ChevyGuy (Dec 13, 2014)

I don't think indirect can give you pressure readings. So I'd have to say you have direct.

I suspect your test drive didn't cause enough check-ins to be missed to cause the light to come on.


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## UpstateNYBill (Jan 14, 2012)

fatmike409 said:


> No, I had already put them away in the garage.


Next to where the Cruze is parked?

So when you start up the Cruze, it is still getting it's readings from those tires. Drive far enough, and the tpms light will eventually come on.


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## ChevyCanuck (Sep 27, 2016)

It took a day for the TPMS readings to "error out" on my Gen 2 Cruze LT after installing winter wheels/tires without TPMS.


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