display ASTON MARTIN V8 VANTAGE 2010 Owner's Manual

AML EOBD System Operation Summary

Rory O’Curry Aston Martin Lagonda CONFIDENTIAL 1 May 2009
rocurry@astonmartin.com AML EOBD Monitors 07 ROC.doc Page 36 of 43

Serial Data Link MIL Illumination

The instrument cluster on some vehicles use the J1850 serial data link or CAN data link to receive and
display various types of information from the PCM. For example, the engine coolant temperature
information displayed on the instrument cluster com es from the same ECT sensor used by the PCM for all
its internal calculations.
These same vehicles use the J1850 serial data link or CAN data link to illuminate the MIL rather than a
circuit, hard-wired to the PCM. The PCM periodically sends the instrument cluster a message that tells it
to turn on the MIL, turn off the MIL or blink the MI L. If the instrument cluster fails to receive a message
within a 5-second timeout period, the instrument cluster itself illuminates the MIL. If communication is
restored, the instrument cluster turns off the MI L after 5 seconds. Due to its limited capabilities, the
instrument cluster does not generate or store Diagnostic Trouble Codes.