thisisnotadrill

I'm a car n00b but pretty well versed in troubleshooting electronics, and I have two issues (or pieces of evidence, if you like) that I'd like to sort out:

1) TPSS warning light blinks for a minute when the car is turned on and then stays on, despite tires being inflated properly. (according to the manual, this indicates a malfunction but does not give any further guidance).

2) Recently purchased new remote entry fob/key (http://cgi.ebay.com/ebaymotors/ws/eB...m=320555480490) because this car was previously repossessed and so was purchased without remote entry keys. I can use the procedure (also used by first gen xB owners) to put the car into programming mode and the key/fob itself lights up when I press its buttons but I can not get the car to acknowledge that I am trying to register a new remote (it won't even turn lock/unlock the doors to tell me that registration failed).

I don't know much about these systems, but I did find one google result which suggested that these could be related in that in some systems the TPSS and remote entry use the same receiver module. However, I dont know if that is true in toyota/scion products in general or in this particular system.

I do plan on getting a replacement key to rule out that possibility, but if it is the car itself what steps can i take to troubleshoot this? Is there a fuse, or wiring that can be checked?

Sefi

If the car has aftermarket wheels on it, make sure it even has sensors installed in the rims. If it has stock steelies...still make sure it has sensors since it was repossessed. Its possible, if someone changed out wheels before you owned it, they put new sensors in the wheels but never had the car programmed to recognize the new sensors also.

thisisnotadrill

The wheels are toyota branded alloy wheels. I can't claim to know exactly what the sensors look like, but all the valves do have a light gray metal sheath surrounding the valve stem and as far as I can tell that does correspond to what the sensor valves should look like (according to a document on the TPWS inside a file I downloaded via link from this site entitled ScionxD2008TIS.zip)

I should say, I'm only really interested in fixing the TPWS in so far as there is a chance it is related to the problems with the keyless entry. According to the TPWS and keyless entry documents found in the TIS, the receivers for both do look roughly similar and are both located in the driver's side C-pillar but there is no indication that they are actually the same device.

I will be taking the car into be inspected tomorrow. if the garage has the proper computer scanning device do you think it would be trivial to diagnose the problem?

thisisnotadrill

alright, new question:

if both the TPWS' and keyless entry's receivers are in the driver's side C-pillar, what is the most likely route for the cables back to the front of the car?

the keyless entry connects to the main body ECU behind the dash between the steering wheel and the drivers side door and the TPWS ECU is roughly behind the upper glovebox on the passenger side.

two.0XD

your tire pressure system, may not have gone bad. This could mean that your battery in one the the sensors is not longer working.
You can take this to a sams club or a costco (be nice when asking) and they have the tool to check it out. if you take it any where else you will be charged, if your lucky they might even reprogram it for you.
This might be a dumb question but, have you tried to reset it your self yet? there should be a switch below the steering wheel that you would have to hold for a few seconds (while the car is in acc). I believe the goal is to have the light blink 3 times, then turn the car on.

thisisnotadrill

Well, I just had to have the car inspected yesterday so I asked the garage to try to hook up the tool necessary to communicate with the computer.

The TPWS system came up with four codes: C2121-C2124. that corresponds, as best as i can tell, to 'no communication with wireless transmitter in wheel X' for the four wheels. I'll give the reset button another shot, I honestly can't remember if I tried holding it while the car was in ACC or when it was on so I'll do it again. But if that isn't the problem its either that all four batteries in the in-wheel sensors are dead (possible, but unlikely?) or there is something wrong with the receiver.

They couldn't communicate with the keyless entry at all, though I am not sure if thats because they didn't have the right tool or because of some issue with the keyless entry system.

Being as though the two systems that aren't working properly have receivers in the same place I think the first thing to check is the cabling between the receivers and the computers that control them.