Cherokee 2WD L4-150 2.5L VIN H TBI (1988)
Electronic Brake Control Module: Description and Operation
Fail Safe Operation
Fig.5 ECU Fail Safe Function
FAIL SAFE FUNCTION
The Electronic Control Unit (ECU) consists of self-test sections, serial link, and a watchdog circuit which is included for the purpose of a system
fail safe (fig. 5). The self-test circuits check for proper operation internal to the signal conditioning and solenoid driver circuits, and also for proper
operation of components outside of the ECU. If a discrepancy is found by any of the safety measures, the operator is alerted by the indicator lights,
the ECU is disabled and the system defaults to normal braking.
