General Specification Electrical Function gmw3110 General Motors Local Area Network Enhanced Diagnostic Test Mode Specification

Table 85: ReadDataByParameterIdentifier (PID=000C hex) 
T = Frame Sent By Tester; N = Frame Sent By Node; shaded region indicates PCI 
Frame Type 
CAN Id 
#1 
#2 
#3 
#4 
#5 
#6 
#7 
#8 
T(USDT-SF) 
$7E0 
$03 
$22 
$00 
$0C 
--- 
--- 
--- 
--- 
N(USDT-SF) 
$7E8 
$05 
$62 
$00 
$0C 
$0B 
$B8 
--- 
--- 
8.6.5.2 Physically Request Multiple PIDs Resulting In Multi-Frame Response. 
In the example below 
(Table 86), the following is assumed true: 

The ECU supports retrieving at least three PIDs in a single request. 

The point to point request CAN Id for the ECU is $7E0. 

The USDT response CAN Id of the ECU is $7E8. 

The PID for Engine Coolant Temperature (as defined in SAE J1979/ISO 15031-5) is $05 (so this service 
requests with $0005). The data returned is a single byte with a transfer function of °C = (N - 40). This 
provides a temperature range from -40 to 215°C. 

Engine Coolant Temperature is assumed to be 92°C at the time of the request. 

The PID for engine rpm (as defined in SAE J1979/ISO 15031-5) is $0C (so this service requests with 
$000C). The data returned is two bytes with a transfer function of rpm = N/4. 

Engine Speed is assumed to be 750 rpm at the time of the request. 

The time since engine start is defined in PID $001F contains two bytes of data with a scaling of 1 s per 
count. 

It is assumed that the engine has been running for 200 s. 
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