Alero L4-144 24L Throttle Position Sensor Component Information
It is important to test terminal contact at the component and any in-line connectors before replacing a suspect component. Mating terminals must be
inspected to ensure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination
or deformation.
Contamination may be caused by the connector halves being improperly connected. A missing or damaged connector seal, damage to the connector
itself, or exposing the terminals to moisture and dirt can also cause contamination. Contamination, usually in the underhood or underbody connectors,
leads to terminal corrosion, causing an open circuit or intermittently open circuit.
Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves, or
repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact
causing an open or intermittently open circuit.
Round Wire Connectors
Follow the procedure below to test terminal contact of Metri-Pack or 56 series terminals. Refer to the J 38125-B Terminal Repair Kit or the J
38125-4 Instruction Manual for terminal identification.
Follow the procedure below in order to test terminal contact.
1. Separate the connector halves.
2. Visually inspect the connector halves for contamination. Contamination may result in a white or green build-up within the connector body or
between terminals. This causes high terminal resistance, intermittent contact, or an open circuit. An underhood or underbody connector that shows
signs of contamination should be replaced in its entirety: terminals, seals, and connector body.
3. Using an equivalent male terminal from the J 38125-B, test that the retention force is significantly different between a good terminal and a suspect
terminal. Replace the female terminal in question.
Flat Wire (Dock and Lock) Connectors
There are no serviceable parts for flat wire (dock and lock) connectors on the harness side or the component side.
Follow the procedure below in order to test terminal contact.
1. Remove the component in question.
2. Visually inspect each side of the connector for signs of contamination. Avoid touching either side of the connector as oil from your skin may be a
source of contamination as well.
3. Visually inspect the terminal bearing surfaces of the flat wire circuits for splits, cracks, or other imperfections that could cause poor terminal
contact. Visually inspect the component side connector to ensure that all of the terminals are uniform and free of damage or deformation.
4. Insert the appropriate adapter from the J 42675 Flat Wire Probe Adapter Kit on the flat wire harness connector in order to test the circuit in
question.
Measuring Frequency
NOTE: Refer to Test Probe Notice in Service Precautions.
The following procedure determines the frequency of a signal.
IMPORTANT: Connecting the DMM to the circuit before pressing the Hz button will allow the DMM to autorange to an appropriate range.
1. Apply power to the circuit.
2. Set the rotary dial of the DMM to the V (AC) position.
3. Connect the positive lead of the DMM to the circuit to be tested.
4. Connect the negative lead of the DMM to a good ground.
5. Press the Hz button on the DMM.
6. The DMM will display the frequency measured.
Measuring Voltage
NOTE: Refer to Test Probe Notice in Service Precautions.
The following procedure measures the voltage at a selected point in a circuit.
1. Disconnect the electrical harness connector for the circuit being tested, if necessary.
2. Enable the circuit and/or system being tested. Use the following methods:
^
Turn ON the ignition, with the engine OFF.
^
Turn ON the engine.
^
Turn ON the circuit and/or system with a scan tool in Output Controls.
^
Turn ON the switch for the circuit and/or system being tested.
3. Select the V (AC) or V (DC) position on the DMM.
4. Connect the positive lead of the DMM to the point of the circuit to be tested.
5. Connect the negative lead of the DMM to a good ground.
6. The DMM displays the voltage measured at that point.
Measuring Voltage Drop
