Interpreters Document

Request 
Byte
Value 
Byte Description 
1 
80 
Format byte for physical addressing 
2 
## 
Global target byte 
3 
## 
Global source byte 
4 
01 
Length of request from byte 5 up to checksum (not included) 
5 
37 
Request Transfer Exit request service ID
6 
CS 
1 byte request checksum 
Calculate checksum and copy into the service request (byte 6) 
Send Request Transfer Exit and receive response (up to 10 Bytes) 
Goto KWP2000 Response Processing
If Request Transfer Exit positive response is received 
Look for Request Transfer Exit positive response service ID ($77) in goto fields 
Else
Look for Request Transfer Exit negative response, response code in goto fields 
Endif
If found
Goto appropriate step
Else 
Goto step indicated by FF goto field 
Endif
Typical Interpreter Line: (all Action and Goto fields are hex numbers) 
Step 
Op-Code 
Action Fields
Goto Fields 
10 
37 
02 04 00 01 
77 11 FF 3D 00 00 00 00 00 00 
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38 Op-Code: SR 38 to Start Utility File Routine by Address 
 
Supported By:
KWP2000 Interpreter 2
 
 
Description: 
The 38 Op-Code will build a standard service request 38 to send to an ECU. This Op-Code is used to start a
Device Specific Control Routine, from the Utility File, that was downloaded to RAM by an Op-Code 90. The 
address information for the service request is read from the routine in the Utility File. This Op-Code also 
supports the option to pass in Routine Entry Options from a Data Routine. For details on how to use this 
feature see the Action Fields and the Pseudo Code. The routine that contains the Routine Entry Options 
should be formatted with a zero load address and a valid length (see description of Data Routines). The data 
portion of the routine should 
only
contain the Routine Entry Options to include in the request with no additional 
data. If the routine execution results in the ECU responding with two bytes of additional data then Op-Code 78 
should be used instead of Op-Code 38.
Action Fields: 
AC0: Routine number from Utility File to get execution address from 
AC1: Routine number from Utility File to use as Routine Entry Options in the Service Request 38 
(Shall be $00 if not used)
AC2: $00 - Not used
AC3: Exceptions: 
$00 - Use address from routine number AC0 
$01 - Use global address information from an Op-Code 'F1' 
Pseudo Code: 
XX 38 AC0 AC1 AC2 AC3 G0-G1 G2-G3 G4-G5 G6-G7 G8-G9 
Use KWP2000 Normal Response processing
Build Start Routine by Address Request as indicated in the table below, contents of the XX locations is
detailed in pseudo code following the table