GM Testing - Snap-on

Chapter 8 <strong>GM</strong>
<strong>Testing</strong> Control Systems Tests (Except ABS)
MAIN MENU <strong>GM</strong> ENGINE
>CODES & DATA
FUNCTIONAL TESTS
CUSTOM SETUP
[PRESS N FOR HELP]
ROAD TEST (NO C&D)
REVIEW MOVIE
Figure 8-9 Sample main menu when data does not transmit during a Road Test
The ROAD TEST (NO C&D) selection removes the resistive load the scan tool applies in
Codes & Data mode and allows the vehicle to be safely driven with the scan tool connected.
After selecting ROAD TEST (NO C&D), the following screen displays (Figure 8-10).
ROAD TEST MODE. OK TO DRIVE.
ECM REMOVED FROM DIAGNOSTIC MODE.
NO CODES OR DATA AVAILABLE.
PRESS N FOR MAIN MENU.
Figure 8-10 Sample ROAD TEST (NO C&D) screen
Codes & Data and Road Test
Many 1986 and later <strong>GM</strong> vehicles provide only the Road Test mode, or “open mode,” for
viewing the engine and transmission data. For these vehicles, CODES & DATA AND ROAD
TEST displays on the MAIN MENU <strong>GM</strong> ENGINE (Figure 8-11).
MAIN MENU <strong>GM</strong> ENGINE OTHER SYSTEMS
>CODES & DATA AND ROAD TEST
FUNCTIONAL TESTS REVIEW MOVIE
CUSTOM SETUP
Figure 8-11 CODES & DATA AND ROAD TEST selection
This mode may be used for testing in the shop, as well as for road testing. Select this function
and the second line of the display shows the vehicle may be driven (Figure 8-12).
RPM__1234 O2(mV)__689 INTEGRATR__128
** CODES AND DATA. OK TO DRIVE. **
NO CODES PRESENT
O2 SENSOR B1______05 O2 SENSOR B2_____06
Figure 8-12 Sample “Codes and Data and Road Test” display
Codes & Data Menu
Some vehicles have a CODES & DATA MENU selection (Figure 8-13), which is used to
access data from various data groups.
MAIN MENU <strong>GM</strong> ENGINE
>CODES & DATA MENU
FUNCTIONAL TESTS
CUSTOM SETUP
OTHER SYSTEMS
TROUBLESHOOTER
Figure 8-13 CODES & DATA MENU selection
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