Diagnostic Trouble Code (DTC) Information ECM-801A

Condition 

Fig 1: Identifying Battery

Courtesy of VOLVO CARS OF NORTH AMERICA.

The diagnostic trouble code (DTC) is stored if the voltage from the system relay to the engine control module (ECM) is below 3 V (Signal missing) or if the power supply from the engine control module (ECM) to the throttle unit is below 8 V (Faulty signal).

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

Substitute Value 

None.

Possible Source 

Signal missing 

• Faulty charging system
• Contact resistance in the terminals
• Open-circuit in the signal cable for the system relay
• Damaged system relay.

Faulty signal 

• Faulty charging system
• Contact resistance in the terminals
• Damaged system relay.

Fault symptom[s] 

• The starter motor does not turn
• The starter motor turns but the engine does not start
• The engine runs poorly.