Contact Resistance and Oxidation

2004 Volvo XC90 AWD L5-2.5L Turbo VIN 59 B5254T2SECTION Contact Resistance and Oxidation


Contact resistance and oxidation







Repair wiring and cable terminals, using appropriate procedures.
In theory, the resistance across contacts, leads and terminals should be 0 [ohm]. However, there is always some resistance due to terminal oxidation.
If this resistance becomes too great the result will be a malfunction. The magnitude of the resistance before it causes a malfunction depends on the circuit load.

Checks:
- Check the cables visually according to "Check Terminals Visually."







NOTE: Do not apply rust solvent spray or grease to the Heated Oxygen Sensor (HO2S) or combined instrument panel connectors.


- Ignition off
- Disconnect the battery negative terminal
- Use compressed air to clean the disconnected connector
- Apply rust solvent spray 1161422 to the disconnected connectors
- Blow clean using compressed air.












NOTE: Do not fill the protective cover with grease.


- Press grease, P/N 1161417-9, into the female sockets directly from tube
- Check that all the terminal cavities are filled
- Use a loose male pin to ensure that the connection in the sockets is good. The pin should remain in position when pulled gently.


RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.