Fail-Safe System; Pre-Programmed Value For Fail-Safe System - Suzuki DF 90 Service Manual

3-30 ENGINE CONTROL SYSTEM

FAIL-SAFE SYSTEM

The fail-safe system is closely related to the self-diagnostic system.
When an abnormality occurs in a sensor signal, the ECM ignores the out-of-range signal and assumes a pre-
programmed value for the failed sensors.
This allows the engine to continue running under the fail-safe condition.

PRE-PROGRAMMED VALUE FOR FAIL-SAFE SYSTEM

FAILED ITEM
MAP sensor 1
CKP sensor
CMP sensor
Cylinder temp. sensor
IAT sensor
Exhaust manifold temp.
sensor
NOTE:
There is no back-up system for the ECM itself. The engine will stop if it has failed.
NOTE 1:
This value will change according to the current engine speed.
PRE-PROGRAMMED VALUE
• 319 – 475 mmHg / (Correspond to approx. 750 – 4000 r/min.) [NOTE 1]
Based on signals from CMP sensor :
• Ignition timing fixed at BTDC 5°
• Normal sequential fuel injection
Based on signals from CKP sensor :
(a) Failed while engine running
• Ignition timing fixed at BTDC 5°
• Normal sequential fuel injection
(b) Failed prior to engine start
• Ignition timing fixed at BTDC 5°
• 1 simultaneous injection for all cylinders per 2 crankshaft rotations
60 °C (140 °F)
45 °C (113 °F)
60 °C (140 °F)