ME9 / P0620 00

Read the instructions below then start the fault diagnostic procedure.

Symptom: Higher idling speed.

P0620 00

Fault symptom

Higher idling speed.

On-board diagnosis

Type of diagnosis:

Continuous

Enable criteria:

Engine running.

Generator active.

(Generator active means L Terminal high)

Fault criteria:

Regulator fault. Period duration is 0%/100% (or internal control module fault).

Checking the wiring harness

Move the wiring harness at several spots and in several directions to reveal intermittent breaks and short-circuits. Check switches, connectors and crimp connections for oxidation, retracted pins and pin clamping force.

Diagnostic help

Diagnosis regards:

Electrical fault in connecting leads or component.

Generator connection for field current (DF). Originates in the internal regulator and shows the amount of period length for which the generator applies field current. Used to calculate generator torque requirement.

Functions in the diagnostic tool related to the fault:

Test value:

•	Alternator F Terminal

•	Alternator L Terminal

Activation:

•	Alternator L Terminal Load Dump

(See also description of readings/activations in diagnostic tool)