Checking the connectors

Fig 1: Identifying Ignition ON

Courtesy of VOLVO CARS OF NORTH AMERICA.

Fig 2: Connecting Connector

Courtesy of VOLVO CARS OF NORTH AMERICA.

Ignition off
Remedy the glow plug electrical terminal and control module connector. Check for contact resistance and oxidation.
Check for damage carefully
Reinstall the components, reconnect the connectors etc.
Ignition on.
NOTE:
It is important that only the ignition is on in order for the heater to start.
Activate the heater.
A buzzing sound should be heard from the heater.

Check that the heater starts and runs.

If the heater now functions, the cause of the fault was loose connections in the connectors.

Other information:
- To access the control module or connect the breakout box, see Connecting the breakout box
- To access the glow plug:
  - For cars manufactured up to w38 2001 inclusive, see Glow plugs, engine coolant heater, replacing
  - For cars manufactured from w39 2001 inclusive, see Replacing the glow plugs of the engine coolant heater .
- See Checking wiring and terminals .
Fig 3: Identifying VCT2000 Diagnostic Tool Symbol In VIDA
Courtesy of VOLVO CARS OF NORTH AMERICA.

Does the heater operate?