Launch FX9000 - Page 47

41
FX9000 User Manual
5.5.5 Tire Pressure Monitor System Reset
This function allows you to quickly look up the tire sensor IDs from the vehicle’s
ECU, as well as to perform TPMS replacement and sensor test.
1. After the tire pressure MIL turns on and maintenance is performed, the tire
pressure resetting function must be performed to reset tire pressure and turn
o󰀨 the tire pressure MIL.
2. Tire pressure resetting must be performed after maintenance is performed
in the following cases: tire pressure is too low, tire leaks, tire pressure
monitoring device is replaced or installed, tire is replaced, tire pressure sensor
is damaged, and tire is replaced for the car with tire pressure monitoring
function.
5.5.6 Gear Learning
The crankshaft position sensor learns crankshaft tooth machining tolerance and
saves to the computer to more accurately diagnose engine misfires. If tooth
learning is not performed for a car equipped with Delphi engine, the MIL turns on
after the engine is started. The diagnostic device detects the DTC P1336 ‘tooth
not learned’. In this case, you must use the diagnostic device to perform tooth
learning for the car. After tooth learning is successful, the MIL turns o󰀨.
After the engine ECU, crankshaft position sensor, or crankshaft flywheel is
replaced, or the DTC ‘tooth not learned’ is present, tooth learning must be
performed.
5.5.7 IMMO Service
An immobilizer is an anti-theft mechanism that prevents a vehicle’s engine from
starting unless the correct ignition key or other device is present. Most new
vehicles have an immobilizer as standard equipment. An important advantage of
this system is that it doesn’t require the car owner to activate it since it operates
automatically. An immobilizer is considered as providing much more effective
anti-theft protection than an audible alarm alone.
As an anti-theft device, an immobilizer disables one of the systems needed to
start a car’s engine, usually the ignition or the fuel supply. This is accomplished
by radio frequency identication between a transponder in the ignition key and a
device called a radio frequency reader in the steering column. When the key is
placed in the ignition, the transponder sends a signal with a unique identication
code to the reader, which relays it to a receiver in the vehicle’s computer control
module. If the code is correct, the computer allows the fuel supply and ignition
systems to operate and start the car. If the code is incorrect or absent, the
computer disables the system, and the car will be unable to start until the correct
key is placed in the ignition.