# TPMS: Actual vs. reported - pressure errors.



## Robby (Mar 1, 2013)

The re- learn only registers position.

The odds of four sensors being incorrect is doubtful.....I use two gauges to prove no gauge fault.

One digital one analog......don't trust stick gauges and the inexpensive digitals are not to trustable.

Good gauges run about sixty bucks but generally are a once in a lifetime investment.

Rob


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## Silver LT RS (Jun 4, 2012)

My TPMS sensors are usually within 1 or 2 psi of my mechanical tire pressure gauge.


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## commutertg (Feb 2, 2013)

When I switched back to my summer tires & rims the TPMS did not register the new tire positions, bu the last recorded when they came off in favor of the winter set (no units in winter set). Do you happen to know how and when it relearns the new tire positions?




Robby said:


> The re- learn only registers position.
> 
> The odds of four sensors being incorrect is doubtful.....I use two gauges to prove no gauge fault.
> 
> ...


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## Robby (Mar 1, 2013)

The GM system must be manually taught (relearn) using a TPMS registering tool the dealer and tire stores have available, but, if you put the wheels back in their original positions I am of the belief you can trigger (wake up) the sensors yourself.
If memory serves (I have my Cruze at my sons shop.....I'm driving my Jeep today) the owners manual has a TPMS section devoted to this.....somewhere in the vehicle set up programming.

Wish I could give you more.

Rob


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## titan2782 (Nov 4, 2011)

We've already figured that the TPMS is off. just figure out how off they are and compensate in your head.


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## Poko (Feb 24, 2013)

I have a 2011 cruze and my readings are spot on to my very accurate digital gauge i use. So i can't comment on any issues.

I work for a chevy dealer and a tpms relearn takes me 30 seconds. 

The tpms system must be manually relearned. It teaches the system the position and the pressure the sensor currently has. The way a dealer does it is as follows. 
Turn the key to the on position before starting this procedure. 

1. In the dic find the tire pressure section. 
2. Hold the set/reset button
3. A screen will pop up confirming you want to relearn the system. 
4. Push the set/reset button. The horn will sound. 
5. Use a tpms activation tool to activate each sensor in this order. LF, RF, RR, LR. The horn will sound after each successful relearn of each sensor. This is your cue to go to the next sensor. When all the sensors have been learned you will here 2 honks confirming it has been reset. 

I personally use this tool, el-50448. It simply activates tpms sensors. It works perfect for gm vehicles. 

I have heard of people using a deflate then inflate method which has had mixed results. 

If all else fails goto a dealer and ask them to reset it, most dealers should do this free of charge especially if you bought your vehicle from them. 

Sent from AutoGuide.com Free App


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## Toyotech (Aug 17, 2012)

Poko thanks for the part number, found it on amazon for 60 bucks and i'll be ordering one.


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## Deadstick (Mar 18, 2013)

I found out my gauge sucked. Other gauge matches the tpms.


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## 70AARCUDA (Nov 14, 2010)

On our 2011 LTZ, the TPMS pressure numbers are typically within ±1 psi of the values shown on my hand-held bourdon-tube gauge...which *was* calibrated once.


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## Poko (Feb 24, 2013)

Toyotech said:


> Poko thanks for the part number, found it on amazon for 60 bucks and i'll be ordering one.


No problem, it is a very cheap alternative to most tpms tools and very easy to use. Also the manual procedure (deflate/inflate) should be disabled on most cars now due to issues that have arisen so this tool is well worth it in my opinion.

The dealer tool that is provided to us at the shop is over $600 bucks and we rarely actually need it. I only pull it out if I really need to know actual sensor information or advanced diag (very rare).
https://gmspecialservicetools.spx.com/ToolDetails.aspx?id=6417

Here is a pdf showing some difference and additional info.
https://gmspecialservicetools.spx.com/Media/Common/Documents/EL-50448_rev_1.pdf


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