User Manual
16
LAUNCH
 TOUCH PRO ELITE User Manual
Trip DTCs.
When a 
Type “A”
 DTC is found on the First Trip, the following events take place:
•  The computer commands the MIL “On” when the failure is rst found.
•  If the failure causes a severe misre that may cause damage to the catalytic 
converter, the MIL “ashes” 
once per second
. The MIL continues to ash as 
long as the condition exists. If the condition that caused the MIL to ash is no 
longer present, the MIL will light “steady” On.
•  A DTC is saved in the computer’s memory for later retrieval.
•  A “Freeze Frame” of the conditions present in the engine or emissions system 
when the MIL was ordered “On” is saved in the computer’s memory for later 
retrieval. This information shows fuel system status (closed loop or open 
loop), engine load, coolant temperature, fuel trim value, MAP vacuum, engine 
RPM and DTC priority.
When a 
Type “B”
 DTC is found on the First Trip, the following events take place:
•  The  computer  sets  a  Pending  DTC,  but  the  MIL  is  not  ordered  “On.” 
“Freeze Frame”  data  may or may  not be saved  at this time  depending  on 
manufacturer. The Pending DTC is saved in the computer’s memory for later 
retrieval.
•  If the failure is found on the second consecutive trip, the MIL is ordered “On.” 
“Freeze Frame” data is saved in the computer’s memory.
•  If the failure is not found on the second Trip, the Pending DTC is erased from 
the computer’s memory.
The  MIL will  stay  lit  for  both Type  “A”  and  Type  “B” codes  until  one  of  the 
following conditions occurs:
•  If the conditions  that  caused the MIL to  light are no longer  present  for the 
next three trips in a row, the computer automatically turns the MIL “O” if no 
other emissions-related faults are present. However, the DTCs remain in the 
computer’s memory as a history code for 40 warm-up cycles (80 warm-up 
cycles for fuel and misre faults). The DTCs are automatically  erased  if  the 
fault that caused them to be set is not detected again during that period.
•  Misfire and  fuel  system  faults  require three  trips  with  “similar  conditions” 
before the MIL  is turned  “O.” These are trips where the engine load, RPM 
and temperature are similar to the conditions present when the fault was rst 
found.
Note: After turning o MIL, DTCs and Freeze Frame data will stay in 
the computer’s memory.
•  Erasing the DTCs from the computer’s memory can also turn o the MIL. If a 










