Diagnostic trouble code (DTC) information ECM-630B

Condition 

Fig 1: Identifying A/C Relay

Courtesy of VOLVO CARS OF NORTH AMERICA.

The engine control module (ECM) checks the signal cable for controlling the air conditioning (A/C) relay.

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) detects an open-circuit in the signal cable for the air conditioning (A/C) relay.

The diagnostic trouble code (DTC) can be diagnosed at ignition on and with the engine running.

Substitute Value 

• None.

Possible Source 

• Open-circuit in the signal cable
• Open-circuit in the power cable
• Damaged air conditioning (A/C) relay.

Fault symptom[s] 

• The air conditioning (A/C) system does not operate.