BW. Checking Cables and Terminals

BWA. Checking Cables And Terminals Permanent Faults.







BWA1. Visual inspection of connections


NOTE: When checking engine control module (ECM), do not remove the control module from the car until the relay has broken the power supply. This can take up to four minutes after the ignition has been switched off and the engine cooling fan (FC) stopped. Terminals should be inspected visually when connectors are opened.

Checks:
Look for oxidation which can damage the connection in the terminals.
Check that the blade and terminals are undamaged, that they are correctly installed in the connector, and that the lead is correctly connected to the terminal. Check the blade and terminals specially for this fault.
Check with a separate loose male terminal that the female terminal gives a good contact. Check that they are properly secured by pulling the terminals.


BWA2. Open-circuit






Open-circuit in a cable becomes apparent when one or more functions are missing. Rubbed and worn cables or loose terminals are common fault causes.

Checks:
Disconnect connectors at both ends of the cable.
Connect an ohmmeter between the ends of the cable.
The ohmmeter should read approximately 0 Ohms if the cable is intact.







Always check that the control module and control module box connectors so that the terminal and connectors are not bent or damaged, this can cause faults. In particular check pins and terminals for the relevant fault, according to BWA1.


BWA3. Short-circuit to ground






A short-circuit between a live cable and ground is often indicated by the loss of a function or a fuse blowing when a current is passed through the cable.

Checks:
Activate all switches and sensors in the circuit and check to see if the fuse blows.
Disconnect connectors to components in the circuit to ensure that they do not affect readings.

Use ohmmeter to measure resistance between lead and ground.
The ohmmeter should read infinite resistance if no components are connected.
In particular check pins and terminals for the relevant fault, according to BWA1.



BWA4. Short-circuit to supply voltage






Short-circuit between a cable and voltage often causes the fuse to blow when the voltage is applied to the cable, or that a function is missing.

Checks:
Use a voltmeter to take readings at various points of the circuit while operating switches and sensors.

Voltmeter readings will depend on the circuit and status of switches and sensors. Use the wiring diagram to determine the correct voltage in the circuit.

Use an ohmmeter between suspect cables to detect short-circuits between them. The ohmmeter should read infinite resistance between leads not connected to each other in the circuit.

The ohmmeter should read infinite resistance between leads not connected to each other in the circuit. In particular check pins and terminals for the relevant fault, according to BWA1.



BWA5. Contact resistance and oxidation






The resistance in contacts, cables and terminals should be 0 Ohms However, a certain degree of resistance will be present due to oxidation of the connections.

If this resistance becomes too great the result will be a malfunction. The magnitude of resistance before it causes a malfunction depends on circuit load.

Checks:
Check cables visually according to BWA1.



Cleaning female socket terminals and male pin terminals






NOTE: Rust solvent spray or grease must not be used on any of the heated oxygen sensor (HO2S) or combined instrument panel connectors.


Ignition off.
Disconnect battery negative lead.
Use compressed air to clean the disconnected connector.
Spray rust solvent spray 1161422 on the disconnected connectors.
Blow clean with compressed air.


Greasing terminals






NOTE: Do not fill the protective cover with grease.


Press grease, P/N 1161417-9, into female sockets directly from tube.
Check that the holes are filled in all the connecting sockets.
Test with a separate loose male pin terminal that the female socket terminal gives a good connection, and that the terminal is secure when pulled lightly.



BWB. Checking Cables And Terminals Intermittent Faults







BWB1. Inspect terminals visually


NOTE: When checking engine control module (ECM), do not remove the control module from the car until the relay has broken the power supply. This can take up to four minutes after the ignition has been switched off and the engine cooling fan (FC) stopped. Terminals should be inspected visually when connectors are opened.

Checks:
Look for oxidation which can damage the connection in the terminals.
Check that the blade and terminals are undamaged, that they are correctly installed in the connector, and that the lead is correctly connected to the terminal. Check the blade and terminals specially for this fault.
Test with a separate loose male pin terminal that the female socket connector gives a good connection and that the terminal is secure when pulled lightly.
Shake cables lightly and pull on connectors during measurement to locate damage.


BWB2. Open-circuit






An open-circuit in a cable will be indicated by the loss of a function (or functions).
Rubbed and worn cables which are loose are common fault causes.

Checks:
Disconnect connectors at both ends of the cable.
Check cable visually according to BWB1.
Connect an ohmmeter between the ends of the cable.

The ohmmeter should read approximately 0 on a cable without open-circuit. Shake the cables lightly and pull on connectors during measurement to locate the damage. If reading is incorrect. Replace cable and/or continue according to BWB6.







Always check the control module and control module box connectors so that the terminals and connectors are not twisted or damaged, this can cause faults. Check the blade and terminals specially for this fault.



BWB3. Short-circuit to ground







A short-circuit between a live cable and ground is often indicated by the loss of a function or a fuse blowing when a current is passed through the cable.

Checks:
Check cable visually according to BWB1.
Activate all switches and sensors in the circuit and check to see if the fuse blows.
Disconnect connectors to components in the circuit to ensure that they do not affect readings.

Connect an ohmmeter between cable and ground.
The ohmmeter should read infinite resistance if no components are connected. Shake the cables lightly and pull on connectors during measurement to locate the damage. If the reading is not correct replace the cable and/or continue according to BWB6.


BWB4. Short-circuit to supply voltage






A short-circuit between a cable and voltage is often indicated by the loss of a function or a fuse blowing when a current is passed through the cable.

Checks:
Check cable visually according to BWB1.

Use a voltmeter to take readings at various points of the circuit while operating switches and sensors. The voltage the voltmeter should read is dependent on which circuit the measurement is carried out on, the switch position and sensor. Use the wiring diagram to determine the correct voltage in the circuit

Use an ohmmeter between suspect cables to detect short-circuits between them. The ohmmeter should read infinite resistance between leads not connected to each other in the circuit. Shake the cable and gently pull on the terminals to determine which cable is damaged. If reading is incorrect. Replace cable and/or continue according to BWB6.



BWB5. Loose connections (terminals)






Loose connections in terminals may be caused by oxidation of the pins and sockets, or by defective connection of a cable to its cable terminal.
Loose connections produce the same faults as an intermittent open-circuit in a cable.
Checks:
Check terminals visually according to BWB1.
Continue according to BWB6.




BWB6. Contact resistance and oxidation






The resistance in contacts, cables and terminals should be 0 Ohms. There is some resistance because of oxidation on the terminals. If the resistance is too great there is function problem. The magnitude of resistance before it causes a malfunction depends on circuit load. A guideline would be a few ohms.


Cleaning female socket terminals and male pin terminals







NOTE: Rust solvent spray or grease must not be used on any of the heated oxygen sensor (HO2S) or combined instrument panel connectors.


Ignition off.
Disconnect battery negative lead.
Use compressed air to clean the disconnected connector.
Spray rust solvent spray 1161422 on the disconnected connectors.
Blow clean with compressed air.


Greasing terminals






NOTE: Do not fill the protective cover with grease.


Press in grease 1161417-9 into the terminals straight from the tube.
Check that the holes are filled in the connectors.
Test with a separate loose male pin terminal that the terminals give a good connection and that the terminal is secure by pulling lightly