Description - engine management (ENGINE MANAGEMENT SYSTEM - V8) (page 41 of 43)

ENGINE MANAGEMENT SYSTEM - V8

18-2-46 DESCRIPTION AND OPERATION

Input/Output
The operation of the ATC request is via a switch being connected to earth. Voltage is supplied via pin 38 of connector 
C0637 of the ECM, at the point at when the switch is pressed the connection is made and the ATC clutch is engaged.

The ATC request can fail as follows:

l

Open circuit.

l

Short circuit to voltage supply.

l

Short circuit to vehicle earth.

l

Wiring loom fault.

In the event of an ATC request failure, the ATC system does not work.

Should a malfunction of the component occur the following fault codes may be evident and can be retrieved by 
TestBook.

P Code

J2012 Description

Land Rover Description

P1535

Air conditioning compressor request 
malfunction

ATC requested when not in standby mode