Equus 3123 - GM Code Reader (1982 - 1995) - Manual (Page 12)

2
2-3 GM
Please read your vehicle’s service manual for proper
connection of vacuum hoses, electrical wiring, and wiring
harness connectors. Check the following areas:
a. All fluid levels
b. Air cleaner and ducts
c. Belts
d. Mechanical linkage associated with sensor
e. Vacuum hoses
f. Spark plugs and wires
g. Electrical wiring
h. Electrical connectors
i. Proper battery voltage
j. Fuel system components
2.3 RETRIEVING SERVICE CODES
• Always observe safety precautions before and during the
testing process.
• Fix any known mechanical problems before this test.
• Have pencil and paper handy.
1. Turn off ignition.
2. Connect the Code Reader to the vehicle test connector.
NOTE: The Code Reader only fits into the connector one way.
3. Set Selector Switch to ECM A-B
position.
4. Turn on ignition. DO NOT
START THE ENGINE.
5. Read codes from the "Check Engine" or "Service Engine
Soon" light (from the "Shift to D2" light - 1991 and 1992
models or the "Temperature" indicator light - 1993 and
subsequent - for Saturn Electronic Transmission codes) on
your vehicle's instrument panel. Be sure to write the codes
down.
NOTE: If the light does not blink, refer to your vehicle's
service manual for information on checking the
circuitry.
• All codes are two digits.