Fault-Tracing Information

Possible source(s)

If the engine starts:
- poor battery voltage.
- open-circuit , short-circuit to ground or short-circuit to supply voltage in cable to data link connector (DLC).
- open-circuit in data link connector power supply, power ground or signal ground.
- defective Volvo Scan Tool (ST), Volvo Scan Tool wiring or adapter box.

If engine will not start:
- short-circuit to ground in 15-supply between fuse and engine control module (ECM).
- open-circuit in 15-supply.
- open-circuit in 30-supply.
- open-circuit in supply from main relay.
- open-circuit in control signal, main relay.

NOTE: If communications problems only occur when starting the engine, connect a battery charger or extra battery.

- start fault-tracing.