Diagnostic Trouble Code (DTC) Information ECM-630D

Condition 

Fig 1: Identifying A/C Relay

Courtesy of VOLVO CARS CORPORATION

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 that the signal from the air conditioning (A/C) relay is too low.

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

Substitute Value 

None.

Possible Source 

• Contact resistance in the terminals
• Short-circuit to ground in the signal cable
• Damaged air conditioning (A/C) relay.

Fault symptom[s] 

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