Diagnostic Trouble Code (DTC) Information

Condition

Fig 1: Identifying Battery

Courtesy of VOLVO CARS CORPORATION

Diagnostic trouble code (DTC) ECM-801A is stored if the voltage from the system relay to the control module is greater than 2.5 V but lower than 3 V (signal missing) or if the power supply for the control module to the electronic throttle module is lower than 8 V (faulty signal). The fault 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
Faulty system relay.

Faulty signal

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

Fault symptom[s]

The engine fails to start
The engine runs poorly.