Diagnostic Trouble Code (DTC) Information ECM-800C

Condition 

Fig 1: Identifying Main Relay

Courtesy of VOLVO CARS CORPORATION

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

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers voltage from the system relay when the relay is deactivated.

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

Substitute Value 

• None.

Possible Source 

• Short-circuit to supply voltage in the power supply cable
• Damaged system relay.

Fault symptom[s] 

• Starting/Engine does not start/Unsure when/at all times