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
Check the fuel pump (FP) and the control module connectors. Check for contact resistance and oxidation and remedy.
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 the function of the heater. See Engine coolant heater, test running .

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 or replace the fuel pump (FP):
  - For cars manufactured up to w38 2001 inclusive, see Fuel pump, auxiliary heater, replacing
  - For cars manufactured from w39 2001 inclusive, see Fuel pump auxiliary heater, replacing .
- For other values, see Signal specification
- 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?