Sensor Read Test Mode
1986-891. Place system in diagnostic test mode and wait for code 55 to appear on display screen.
2. Press ATM button on tool to activate display. A specific sensor read test can be called by holding ATM button down until desired test code appears.
3. Slide read/hold switch to Hold position to display corresponding sensor output level.
Sensor Read Test Display Codes
Code Description
01 - Battery temperature sensor - display number ÷ 10 equals sensor temperature.
02 - Oxygen sensor voltage - display number ÷ 10 equals sensor voltage.
03 - Charge temperature sensor voltage - display number ÷ 10 equals sensor voltage.
04 - Engine coolant temperature sensor - display number x 10 equals degrees of engine coolant sensor.
05 - Throttle position sensor - display number ÷ 10 equals sensor voltage.
06 - Peak knock sensor voltage - display number is sensor voltage.
07 - Battery voltage - display number is voltage.
08 - MAP sensor voltage - display number ÷ 10 is voltage.
09 - Control switches (1987-89) - cruise Off, display is blank; cruise On, display shows 00; cruise set, display shows 10; cruise Resume, display shows 01.
10 - Fault codes erase routine (1988) - display will flash 0's for 4 seconds.