Installation Manual

Electrical & Electronic Application And Installation Manual
Production Release Version 1.0
Page 154
11.10.3 Idle Validation Switch
Analogue devices must use an idle validation switch. The idle validation
switch is required to validate that a change in signal is indeed valid and not a
potential electrical fault. Two parameters need to be defined for correct
operation. When configured the engine ECM continually monitors the speed
demand request and the Idle validation switch.
Idle validation maximum ON threshold (Closed)
The value is defined as percent raw signal. At low idle the Idle Validation
switch should be ‘ON’ (the input should be switched to ground). When
increasing engine speed the ECM will continually monitor the idle validation
switch. The switch needs to have switched ‘OFF between the two IVS
thresholds. If the switch state does not change by the ‘ Idle validation
maximum ON threshold’ the ECM will invoke the limp home strategy and the
throttle will not respond.
Idle validation minimum OFF threshold (Open)
The value is defined as percent raw signal. At high idle the Idle Validation
switch should be ‘OFF’ (the input should be switched to open). When
decreasing engine speed the ECM will continually monitor the idle validation
switch. The switch needs to have switched ‘ON’ between the two IVS
thresholds. If the switch state does not change by the ‘ Idle validation minimum
off threshold’ the ECM will invoke the limp home strategy and the throttle will
not respond.