[baroudeur]

Wrong model but i20 forum is lacking in posts and information so perhaps someone on here can help.

My wife is running a 2015 i20 new generation which has a TPMS with just a warning icon light, no pressures or wheel location given.

The TPMS light came on recently but, on checking, the pressures all were correct. A forty minute drive then failed to extinguish the light as the handbook advises so I contacted the dealer.  I was told to set all tyres to 33psi and drive for 20 minutes.....which had no effect not unexpected considering the car  had driven for 40 minutes earlier. Why altering pressures by 1 - 2 psi would have any effect is beyond me.

The next day I was on my way to the dealer when I was delayed on a narrow lane by an accident ahead. Needing to divert  I had to make a 3 point turn during which my nearside  front wheel went onto the grass verge and  as I accelerated it caused that wheel to spin.  As this happened the TPMS light went off. 

Complete mystery..
Why did light come on when tyre pressures were correct?
Why did usual reset process of driving 20 minutes not reset the light?
Why did wheel spin turn off light?

[AlanHo]

Do you know whether the i20 TPMS has pressure senders in each tyre valve - or does it use the ABS sensors to determine that one wheel is running faster than the others because its effective diameter is reduced?

[Phil №❶]

Good thought, Alan 

[cruiserfied]

The warning light TPMS is the low line system and under normal operating conditions sets the warning light when a difference in pressure is sensed at any sensor.
If the sensors have a fault or cannot be read it will set the light.

When left for a while the sensors will go to sleep and need to be driven to wake them up.

Did you take it to the dealer still, did they check for DTC's?

Bit of a stab in th dark but It could be a sticking sensor and the rapid acceleration from the wheel spin rather than gentle acceleration of normal driving could have been enough to activate the sensor.

[baroudeur]

Sorry for the delay but I have been in Germany for a week and decided to take this car rather than leave my wife with a possible problem whilst I was away..

As I left for Dover  the light flashed up again and two minutes later went off again.  Did I curse!  However, 700 miles later the problem did not recur.

I think that the advice to change the pressures was because the dealer assumed it was the previous model i20 which has 33/33 pressures compared to the 34/31 of the later model.

@ Cruiserfied: So, the TPMS detects  a drop in pressure to a set value?  When  the pressure is increased from 31 to 38psi as required for maximum load and it it still only activates at the  set (low)pressure it means a very large under-inflation.

If rapid acceleration cured (?) the problem then 105mph on German autobahns should have unstuck anything.

What is DTC?

[AlanHo]

DTC = Dynamic Traction Control

[ibrokeit]

I think you're incorrect in this case Alan. Rather...

Diagnostic Trouble Codes   within the context of 'did they check for DTCs'

[AlanHo]

My bad - I think you have a point

Hyundai Specific Diagnostic Trouble Codes


Code

Description


P1100
Manifold Absolute Pressure (MAP) Sensor Malfunction (Open/Short)

P1102
Manifold Absolute Pressure (MAP) Sensor Malfunction - Low Voltage

P1103
Manifold Absolute Pressure (MAP) Sensor Malfunction - High Voltage

P1147
ETS Sub Accel Position Sensor 1 Malfunction

P1151
ETS Main Accel Position Sensor 2 Malfunction

P1155
ETS Limp Home Valve

P1159
Variable Intake Motor Malfunction

P1171
Electronic Throttle System Open

P1172
Electronic Throttle System Motor Current

P1173
Electronic Throttle System Rationality Malfunction

P1174
Electronic Throttle System #1 Close Malfunction

P1175
Electronic Throttle System #2 Close Malfunction

P1176
ETS Motor Open/Short #1

P1176
ETS Motor Open/Short #2

P1178
ETS Motor Battery Voltage Open

P1330
Spark Timing Adjust Malfunction

P1521
Power Steering Switch Malfunction

P1607
Electronic Throttle System Communication Error

P1614
Electronic Throttle System Module Malfunction

P1632
Traction Control System Malfunction

[cruiserfied]

DTC - Diagnostic Trouble Codes

The warning light will activate when one sensor is out by a certain amount in comparison to others not a preset pressure.

[baroudeur]

DTC - Diagnostic Trouble Codes

The warning light will activate when one sensor is out by a certain amount in comparison to others not a preset pressure.

Thank you Cruiserfied.

DTC = OBD codes.  I have an OBD2 app and bluetooth interface so will see if anything comes up.

Is the TPMS warning light comparison across an axle or comparing all four pressures?

I ask because the full load pressures on the rear axle goes from 31 to 38psi whereas the front axle goes from 34 to 35 psi so the comparison range will become quite different but there is no physical reset required.

I did try reducing  the pressure in one tyre in 5 psi blocks but failed to get a warning light (ignition on) even when down to just 10psi but this was whilst stationary so, presumably, the car needs to be moving to activate the TPMS? ..

Next problem....winter tyres and TPMS.

[cruiserfied]

Hmmm thats a good question. The way I know it is across all 4 tyres. But you should only be running higher pressures short term.
Pretty sure the sensors IDs are programmed to the vehicle so you would either need to put your winter tyres on the original rims or use rims with sensors and have them programmed when swapped.

[baroudeur]

Hmmm thats a good question. The way I know it is across all 4 tyres. But you should only be running higher pressures short term.
Pretty sure the sensors IDs are programmed to the vehicle so you would either need to put your winter tyres on the original rims or use rims with sensors and have them programmed when swapped.

I think that the activation pressure for the TPMS must be a fixed value and only works whilst moving to trigger the sensor.

Having a set of 205/55 x 16 winter tyres used for one season on my previous i30I would like to fit them to 4 stud 16" steel wheels for the i20 but this means having suitable sensors fitted or running without TPMS through the winter.

Alternatively, I can fit the tyres to the existing i20 alloys and assume the TPMS will not need resetting.