Diagnostic Trouble Code (DTC) Information ECM-801B

Condition 

Fig 1: Identifying Main Relay

Courtesy of VOLVO CARS CORPORATION

The engine control module (ECM) checks the system relay.

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) detects that the voltage on the signal cable for the system relay is lower than a certain value.

The diagnostic trouble code (DTC) can be diagnosed when the ignition is switched on.

Substitute Value 

• None.

Possible Source 

• Short-circuit to ground in the signal cable
• Damaged system relay.

Fault symptom[s] 

• The engine does not start.