Engine Running Test Mode

Be sure to apply parking brake and/or block wheels before performing idle check or adjustment, or any engine tests.
This system monitors sensor output signals as received by the SMEC while the engine is running. The engine running test mode can be performed with the engine idling in neutral with parking brake on or while driving down the road. With the Diagnostic Tool read/hold switch in the read position, the engine running test mode is initiated after the engine is started.
It is also used to establish some specific engine running conditions required for diagnosis.
1. With tester connected and engine running, oxygen system switching displayed and Read/Hold switch in the Read position, press and hold the ATM button until the desired engine running test code appears on the display, then release button. Move Read/Hold switch to Hold position. The readout box will now display output of the selected sensor or run the engine in a specified mode for diagnosis. All readings displayed are to be divided by 10, except coolant sensor and engine RPM which are to be multiplied by 10 and battery voltage, manifold vacuum and vehicle speed are actual.
Engine running test display code descriptions are as follows:
Oxygen sensor state--display will toggle between 0 and 1.
a. 61--Battery temperature sensor - display number divided by 10 equals volts.
b. 62--Oxygen sensor - display number divided by 10 equals volts.
c. 63--Intake charge temperature sensor - display number divided by 10 equals volts.
d. 64--Engine coolant temperature sensor - display number x 10 equals degrees F.
e. 65--Throttle position sensor - display number divided by 10 equals volts.
f. 67--Battery voltage sensor - display equals volts.
g. 68--Manifold vacuum/pressure sensor - display is inches Hg.
h. 69--Minimum throttle position sensor - display number divided by 10 equals volts.
i. 70--Minimum airflow idle speed sensor - display number x 10 equals Rpm.
j. 71--Vehicle speed sensor - display is mph.
k. 72--Engine speed sensor - display number x 10 equals Rpm.