I've never paid much attention to the tire pressures shown on the DIC, which always seem to be way off anyway. My trusty 20 year old SnapOn gage, and cold tires every other Sunday morning, still give me accurate readings. Even the owner's manual recommends doing it this way.

But now, on start-up every morning, I'm getting the idiot light and "Check RF Tire Pressure" from the DIC. When I check with the gage, all pressures--not just the right front--are right where they should be. The light goes out after a few miles of driving. Only happens first thing in the morning and at no other time of the day. I just started the truck a few minutes ago (early evening) after letting it sit for more than 24 hours. No light, no DIC warning.

I know the DIC has to relearn tire positions after a rotation. Is there a way of resetting the pressure monitor as well, or do I simply have a dying sensor which needs to be replaced?
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1988 Mercedes Benz 560SL (Wife's)
1998 Mercedes Benz S420 (Wife's)
1995 Mercedes Benz C280 (Daughter's)

2007 Chevrolet Suburban K2500 3LT (MINE)
1978 Cadillac Fleetwood 75 Limousine (awaiting restoration)<!-- / message --><!-- / message --><!-- / message --><!-- edit note --><!-- / message -->

 

Maybe the battery in the sensor is going south.

 

Either way--bad sensor or battery--the tire has to be dismounted, remounted and balanced, right?
____________________

1988 Mercedes Benz 560SL (Wife's)
1998 Mercedes Benz S420 (Wife's)
1995 Mercedes Benz C280 (Daughter's)

2007 Chevrolet Suburban K2500 3LT (MINE)
1978 Cadillac Fleetwood 75 Limousine (awaiting restoration) <!-- / message --><!-- / message --><!-- / message --><!-- edit note --><!-- / message -->

 

what are you setting the pressures at?

bump the pressure to 2psi over the placard setting to prevent pressure drop during cold mornings.

If the tpm warning telltale is on solid; its just low pressure and the system is working normally. If the telltale is flashing, there is a fault with the system.

 

IIRC the sensor trips at about 20 psi.

Yes, the tire would have to be dismounted, remounted, and rebalanced if the sensor or battery requires replacement.

 

<!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:PunctuationKerning/> <w:ValidateAgainstSchemas/> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> <wontGrowAutofit/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 9]><xml> <w:LatentStyles DefLockedState="false" LatentStyleCount="156"> </w:LatentStyles> </xml><![endif]--><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} </style> <![endif]--> Agreed, sounds like a sensor issue.

Louis
GM Customer Service

 

The guys over at Discount tire tell me that they have a tool to read the tire pressure sensor and can tell what the status of the battery is... I have not had them do it yet but it might be worth a trip to a tire shop to see what they can tell you...

I was going to have them all replaced when I do my tires, the service writer told me not to replace them until they fail..and not do it as a preventive...

 

you can replace them whenever you want its just a matter of coughing up the cash.

The sensors aren't "awake" after they sit so either the tiring being cold as mentioned before is the issue or possibly the battery in the sensor is actually fading out and straightens itself up when you start driving, personally I'd bump the pressure up a few pounds and see what happens

 

If the tire pressure is set to the sticker in the door and the DIC shows the pressure is the same as what your hand held gauge reads then there most likely is something else wrong. I would try bumping up the psi a few more too see what happens (as stated above) if the light stays of then there is a mis match between your old gauge and the tpm sensors. You stated that the DIC pressures are way off but maybe it is your gauge. Just because it is snap-on it does not mean it can not go bad. Any good shop should have a TPMS tool that can read data and battery life. Also the higher end scan tools can access any TPMS data and check for TPMS codes.

 

This would be a waste of money as OE (would not recommend any aftermarket as I have seen too many problems) sensors are around $89 each. Most of the ones I have had too replace were damaged in some way. Even if they fail after you get tires to have one tire dismounted and rebalanced the cost should be no where near 89. labor or $354 if you do all preventively