4.8 is tpms light(SOLVED)
 

So confused. Now this. This is also saying they're basically sensors per wheels. Let me compare what it says about the e46 which I absolutely know uses speed sensors to function.
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Tyre pressure control (RDC)

Introduction
The task of the tyre pressure control system is to remind the driver in good time to check the tyre pressure as it decreases and to warn him in the event of a flat tyre. The RDC system therefore enhances vehicle safety and convenience for the driver. Nevertheless, decision priority and responsibility remain with the driver.

Advantages:

- Increased driving safety by early warning in the event of rapid pressure loss

- Tyre damage caused by excessive flexing in conjunction with low tyre pressure is avoided

- Deviations from set tyre pressure are monitored

- Slow pressure loss is recognized in good time

Components:

- Control unit for signal evaluation

- One receive aerial per wheelhouse

- Wheel electronics with valve

- Initialisation button

Messages to driver
Soft warning: This operating status is characterized by a minimum tyre pressure (0.2 bar under set pressure) at which driving safety is still ensured. The driver is requested via the check control to correct the pressure.

Hard warning: Driving safety is no longer ensured, the driver is requested to check the tyres immediately.

A hard warning is active when the pressure loss drops either 0.4 bar or 16% below the set pressure value or drops below a value stored in the control unit.

Important
Initialisation must always be carried out after every tyre pressure correction. For this purpose, the initialisation button is pressed (min. 6 seconds) with the ignition switched on until the "tyre pressure set" appears in the check control. After several minutes driving time during which the system carries out wheel identification and a plausibility check, the RDC adopts this tyre pressure as the setpoint to be monitored.

Important
The following display texts can appear in the check control: Tyre pressure set, tyre monitoring inactive, check tyre pressure, tyre failure, tyre failure front right, tyre failure front left, tyre failure rear right, tyre failure rear left

System description
The wheel electronic units are mounted within the tyres and measure the tyre pressure as well as the tyre temperature. The measured data are sent from the wheel via an output stage in the wheel electronic unit. The power is supplied by a lithium battery in the wheel electronics. Each electronic control unit features its own code which is also sent during each data transfer.

The data sent by the wheel electronic units are received via aerials mounted in the wheelhouse and transferred via shielded cables to the control unit.

As part of the wheel identification procedure, the system automatically learns what wheel electronic units belong to the vehicle. This function ensures that data from another vehicle cannot be evaluated.


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Verify which system you have - TPMS or FTM.

TPMS will have a pressure sensor and transmitter in each valve stem - they look rather different from a regular rubber and brass valve stem...

http://www.team-bhp.com/forum/attach...ru-ag-tpms.jpg

Note that parts A & B, along with the left end of part C are inside the wheel and not visible without removing the tire from the rim. NEVER undo part E unless you have the tire off the rim! :D

With FTM you will have the regular rubber and brass valve stem (although there are metal versions around).

If you have the FTM system, which uses wheel speed sensors to calculate tyre rotational speed differences, you won't get a response to queries on the TPMS module with INPA etc. as there is not one fitted.

If you have TPMS, then there maybe an issue with one or more of the sensors and further diagnostics is required. I think the batteries in the sensors are good for a quite a ling time but they can (and do) eventually go flat, requiring the sensor be replaced.

Aahhhhhhhhhh. Ok. Ok. Thank for that clarification on the module. Makes sense now.
I think I have rubber FTM valves. Will have a look see at some point.

If it is indeed FTM, and my ride height has not changed. Why the hell cant I reset it then?


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Perhaps one tyre is flat...? ;)

But being serious, have you tried the correct reset procedure as outlined by Overboost (originally from QSilver7)on post #4 of this thread...?

Yep. I sat in there with the manual and tried it and nothing. Light will not go away. Doesn't flash. Nothing. It's like it's broken or some shit. Which makes no sense as I have no abs do dsc errors.

Maybe I can't read. I'll have the woman try it. Since she will do exactly as she reads.


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Hey Snik...you ever find resolution to your FTM issue. My FTM light is what ultimately did in my air susp setup (moved to H&R + Bilstein B6). That being said, my stupid FTM light has remained on no matter what I try to do to reset it. I had my ride height sensors checked within a few months of issues and they checked out (swapped with a new one on each side, independently, to get a ride height reading) so I *think* my issue does not relate to those...but could it possibly be one of my ABS/DSC sensors or probably not since I have no errors for those? How is your issue going?

Adam

Nope. It goes away for a few days if the vehicle is without the battery. Then comes back all fierce and shit. I don't even pay attention to it anymore

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