ad3022s3000a

Electronic idle speed control (ISC) diagnosis operational check

Type ad · topic 30.22 · version 0101 · 2003-06-20

Applies to: ENGINE 104.9, 111.9, 601.9 in MODEL 638

Where it sits

Function group 1 Engine › 30 Throttle control, speed control systems › 30.22 Idle speed control (ISC) — Series 601 (models 9**) · Series 638

Also applies to engines/gearboxes: 104 9**, 111 9**

AD30.22-S-3000A

Electronic idle speed control (ISC) diagnosis operational check

18.8.97

ENGINE 104.9, 111.9, 601.9 in MODEL 638

Electronic idle speed control (ISC)
diagnosis previous knowledge

AD30.22-S-2000A

The operation of the electronic idle speed control (ISC) can also be tested with the HHT using the menu point Actuations. In this case, the HHT can be used to specify the engine speed. If this is not possible, read fault memory and, if the notes provided there do not help, carry out the electrical test routine in full.

a

Battery voltage 11-14 V

b

Fuses F73 and F74 o.k.

c

HHT not connected

Operational check

Test of

Operation/Requirement

Specification

Possible cause/Remedy

ISC operation

Start engine and switch on all consumers

Engine speed remains constant even when all electrical consumers switched on

AD30.22-S-6000A

ISC operation

Unplug connector Y56.1 from ISC actuator.

Start engine and switch on all electrical consumers.

Engine runs at lower speed and irregularly.

AD30.22-S-6000A

Referenced documents