Sarge64

Hi, I am newbie to this forum, but for a while have been a behind the screen observer to the GX issues and solutions, I finally had to get into this forum, as I did search a lot for Tire Pressure warning. Recently my cluster shot a warning for the Tire Pressure, went to the dealer, and he said all my transmitter within the Tire Pressure have been shot. And all needs replacement. Now the job to do by the dealer and re-program with the parts are ***********G high. I do have the transmitter, and the DTC which i picked up long back during my flying days, Have recently upgraded the software, would anyone know how to store these values within the ECM. thanks

mann777

Sarge if you have the DTC tool, the is very easy job to do it, I will take you thru the sequence, which will make it easy on you.
1. First Ensure you have all the Five Tire Pressure Valves id numbers recorded on a paper with you. Make sure you have recorded this information prior to installation. Ensure your tires are inflated to the standard PSI.( Labelled on the Driver Door Frame or Glove Compartment).

2. Each Valve ID number are embedded with a Valve ID transmitter Number on the outer casing.
3.They are printed and be easily recogonized.
4. Now insert the DTC tool to the harness connector below the Driver Footwell where they are connected normally. And got the Diagnotics Menu and choose "Tire Pressure".
5. Now choose Utility under the sub option, and you the only option to register the Tire set.
6. Here you have two options. (a) Main Set (b) 2nd Set. Select Main Set for which you want to register the values of the tires. Once you press, a message would pop up asking do you want to ( of course ) Press Yes. And here you will 5 minutes to enter all the values.
7. Enter No of tires 5 and enter the codes below and press Enter again once you have completed. You will come up with a message, Registration Successful.
8. Now set the values of each Tire PSI values. Normal Front is 32 and Rear is also 32 and also the same for the spare tire.
9. Insert you Ignition key and only move it to the position "ON", and not start.
10. Now remove the DTC tool and reinsert again this time on the screen choose Signal check, Now it will not accept for the first time, so just move to all four wheel quickly and reduce the pressure rapidly, this theECM detect and force feeds the values of the Tire Pressure and the ID numbers instantly. That's it, Now to check if the transmitter values are registered, Inflate the tires to the OEM standard. And if the warning does not come up, that's it, good to go, Hope this helps,
Curious - How did you manage to get the Software updated, was it online, as the one I have is one version older.
thks

Sarge64

Thanks Mann777, i just completed the instruction step by step, I have no words to describe, it has been perfect. And back to road, The GX so far has no warnings on the Instrument cluster. You have just saved me 600/- SQD. If you happen to visit Singapore you entire stay trip will be on me. Great Knowledge.Keep it up. It is because of you such experienced members of CL that keeps this Knowledgeable forum for the Lexus Owners going.

mann777

thanks sarge, for yr compliments, i do keep coming down to visit my clients in Singapore Airlines, sure will bump into you. Welcome to the forum, we have great members and share a wide spectrum of their knowledge and experience. so long !

redtie

Mann777: I have the same problem as Sarge64 but don't have all the stuff that he's got. Is there any other way to reset the warning light? I set the tire pressure to 32psi (per sticker on driver side) and tried to reset it by pressing the tire pressure button under the steering wheel. Nothing happened...thanks

mann777

Redtie what you may have is cyclic system error, So i need to know certain things if you have done.
1. Have u rotated the tires recently.
If yes then the ID values get interchanged in the ECM,If Yes then u need to goto AutoZone and have the data entered via the scan tool. if no goto 2 Question

2. Have u replaced the tires recently.
If yes, you need to initialise the TPWS switch, which is in the Glove compartment( procedure mention in the para below) . If no goto the Third part.

3. If you have note replaced the Tire or Rotated, then the issue you have all Tires are not having exact PSI to the values as standard, a slight difference would trigger a warning from the Issue. Maintain the PSI and set it to as per the Tire Pressure Specification label on the Glove Compartment.

INITILISATION PROCESS
To initialise you need to have the tech stream tool as Tire pressure Valve IDs and the regulated Tire PSI needs to be entered . You can two set of values in the following conditions.
If the Main and 2nd Switch is in UP position The ECU will read the main set of the Tire PSI and Valve ID numbers values.( Ideal this is for regular use)
OR
If the Main and 2nd Switch is in DOWN position The ECU will read the Second set of the Tire PSI and Valve ID numbers values stored differently for any other ride condition such as Snow etc

Hope this helps

mann777

Also do note Tire Pressure Compensation depend on the Tire Pressure and Tire Temperature. I hope you are inflating it while the Tire are at Cold Stage. Tire Pressure is dependent on "cold" tire pressure , driving distance and speed, ambient temperature and road surface temperature. As the temperature of the tire changes, air in the tire expands and contract changing the tire pressure. The cold tire pressure needs to be adjusted accordingly. Seasonal temperature change can dramatically alter tire pressure and which can cause tire pressure warning to illuminate.