jfprl

My hyperactive TPMS system went off again today. Got code 37. Does anybody know what that means?

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click the info button and choose messages function, it should tell you what it is

jfprl

Thanks- the info button just tell you there is a problem not the cause. I looked it up and the code says there is a low battery in the sensor. Off to the dealer..............

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Jfprl,
If you look at the vehicle symbol in the MID, it should indicate which wheel sensor battery is low.
Good luck

ed111

Where are these wheel sensor batteries located? Are they owner-serviceable, or do they require dealer involvement? How long do they last? What kind of battery?

jfprl, which year RL do you have - how long since these batteries were new on your car?

jfprl

The batteries are inside the wheel sensors attached to the inside of the wheels. As far as I know they are not user replaceable. I believe the whole sensor needs to be replaced. I am at 50,000 miles and 2 1/2 years old.

Chas2

It looks like there is no way to replace the battery in the TRW TPMS used in the RL. Actually, the TPMS appears to be a JV between TRW and Michelin called En-Tire Solution

http://www.trw.com/extlink/1,,,00.ht...om#38amp;DIR=1

If you believe Wikipedia, 7-10 year battery life for TPMS is required.
http://en.wikipedia.org/wiki/Tire_pr...itoring_system

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i think what jfprl has is a faulty sensor.
Even if the TPMS battery can be replaced, you still need to dismount the tire, so the dealer is the only place to go

ed111

I just reviewed the pages in the TRW and Wikipedia links provided by Chas2 above. I am concluding that, unlike some other cars, the RL's tire pressure system is a type which does NOT have to be re-initialted or re-programmed when changing or rotating tires. Rather, it "learns" to reconfigure itself so that it properly identifies which wheel location is associated with each sensor.

Is this correct?

Chas2

That is correct. The car does relearn after driving a few miles or after some time sitting. I think that after a certain number of responses from each corner of the car, the computer resets itself to the signals it is getting from each corner of the car.

I believe, when the ignition is off, the TPMS is interrogated at a very low frequency, say once per hour or longer. But when the ignition is on, it interrogates once every minute, and that interrogation rate may even increase with speed of the car. But the point is the car learns that the TPMS sensors have changed positions on the car, and reflects that info in the MID.