Firebird V8-5.7L VIN G (2001)
showing the minimum and maximum values for all frames captured. This is helpful, especially if the fault occurs only once and does not set a DTC.
Test Lamp
TOOLS REQUIRED
J 34142-B Unpowered Test Light
NOTE: Refer to Test Probe Notice in Service Precautions.
A test lamp can simply and quickly test a low impedance circuit for voltage.
The J 34142-B is Micro-Pack compatible and comprised of a 12 volt light bulb with an attached pair of leads.
To properly operate this tool use the following procedure.
1. Attach one lead to ground.
2. Touch the other lead to various points along the circuit where voltage should be present.
3. When the bulb illuminates, there is voltage at the point being tested.
Testing For a Short To Voltage
NOTE: Refer to Test Probe Notice in Service Precautions.
The following procedure tests for a short to voltage in a circuit.
1. Set the rotary dial of the DMM to the V (DC) position.
2. Connect the positive lead of the DMM to 1 end of the circuit to be tested.
3. Connect the negative lead of the DMM to a good ground.
4. Turn ON the ignition and operate all accessories.
5. If the voltage measured is greater than 1 volt, there is a short to voltage in the circuit.
Testing for Continuity
NOTE: Refer to Test Probe Notice in Service Precautions.
The following procedures verify good continuity in a circuit.
With a DMM
1. Set the rotary dial of the DMM to the Ohms position.
2. Disconnect the power feed (i.e. fuse, control module) from the suspect circuit.
3. Disconnect the load.
4. Press the MIN MAX button on the DMM.
5. Connect one lead of the DMM to one end of the circuit to be tested.
6. Connect the other lead of the DMM to the other end of the circuit.
7. If the DMM displays low or no resistance and a tone is heard, the circuit has good continuity.
With a Test Lamp
IMPORTANT: Only use the test lamp procedure on low impedance power and ground circuits.
1. Remove the power feed (i.e. fuse, control module) from the suspect circuit.
2. Disconnect the load.
3. Connect 1 lead of the test lamp to 1 end of the circuit to be tested.
4. Connect the other lead of the test lamp to battery positive voltage.
5. Connect the other end of the circuit to ground.
6. If the test lamp illuminates (full intensity), then the circuit has good continuity.
Testing For Electrical Intermittents
Perform the following procedures while wiggling the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching
the test equipment.
^
Testing for Short to Ground
^
Testing for Continuity
^
Testing for a Short to Voltage
If the fault is not identified, perform the procedure below using the MIN MAX feature on the J 39200 DMM. This feature allows you to manipulate the
circuit without having to watch the J 39200. The J 39200 will generate an audible tone when a change is detected.
IMPORTANT: The J 39200 must be used in order to perform the following procedure since the J 39200 can monitor current, resistance or voltage
