3. Diagnostics Applications
18
3.2. Diagnostic Trouble Codes
The Diagnostic Trouble Codes functions allow
you to read and clear diagnostic trouble codes
(DTCs) from a vehicle.
3.2.1. Read Codes
The Read Codes procedure varies for each vehicle
being tested. This section includes the following
Read Codes procedures:
To read DTCs, please follow these steps:
NOTE: Read Codes can be performed with
both KOEO (Key On Engine Off) and KOER
(Key On Engine Run).
Figure 3.25: Function Menu Screen
1. With the Function Menu screen displayed,
click on Read Codes. This displays the Read
Codes menu screen.
Figure 3.26: Read Codes Screen
2. Click on one of the options that may appear
on the Read Codes screen.
Save - saves the code results for later review.
Print - prints the code results.
3. When finished viewing the list, click on the
Esc button to return to previous screens.
NOTE: When a Benz is being tested, DTC
will be stored in two forms: Fault Codes and
Event Memory. You may not see any trouble
codes in the option of the Fault codes if the
codes are actually stored in the Event
memory.
Figure 3.27: Read Codes Example – Benz
3.2.2. Erase Codes
After reading and / or reviewing the diagnostic
trouble codes, use the following steps to erase the
codes from the vehicle. If Erase Codes is not an
available menu option, consult the manufacturer’s
service manual for the correct “clear code”
method.
NOTE: This Erase Codes function clears the
DTCs from the selected ECU or provides
instructions for how to manually clear the
codes from the ECU.
NOTE: Before performing this procedure,
make sure the vehicle’s ignition key is in the
On (Run) position with the engine off.
To Erase DTCs, please follow these steps:
1. With the Function Menu screen displayed,
click on Erase Codes. This displays an
instruction screen.
2. Follow the instructions on each screen that
appears until the procedure is complete.
3. When finished, use the Esc button to return to
previous screens.
4. Check the codes again. If any codes remain,
repeat the Erase Codes steps.
