Checking Supply

Check the supply to Combustion Preheater Module (CPM) #9 for contact resistance and oxidation as described in, see CONTACT RESISTANCE AND OXIDATION , or a loose connection as described in LOOSE CONNECTIONS (TERMINALS) . Also check fuse 9 in the engine compartment.

Check the cable between #1 on the Ext-X relay (2/29) and #15 on the Combustion Preheater Module (CPM) for contact resistance and oxidation as described in, see CONTACT RESISTANCE AND OXIDATION , or for a loose connection as described in LOOSE CONNECTIONS (TERMINALS) . Also check the relay (2/29), the supply to the relay and passenger compartment fuse 24.

Check that the ground lead is undamaged by checking the cable between additional heater #3 and the ground terminal.

Also check the intermediate connectors.

Other information: 

• To replace the relay, see CENTRAL ELECTRONIC MODULE (CEM), REPLACING .
• For other values, see SIGNAL SPECIFICATION .

Remedy as necessary.

Fig 2: Identifying Connector Terminals

Courtesy of VOLVO CARS CORPORATION

Fig 3: Identifying Ohmmeter

Courtesy of VOLVO CARS CORPORATION

Fig 4: Identifying Connector Terminals

Courtesy of VOLVO CARS CORPORATION

Refer to VERIFICATION