Vehilcles have many options in one type of ECM. So automatic recognition function is applied. The options that can be recognized are MT/AT, 2/4WD, DPF, etc). When a ECM is installed to vehicle, these options recognition are performed by the ECM automatically as checking whether ground line is grounded or opened every IG KEY ON process.
If this recognition is not fulfilled well or any error occurs during the process, engine power generation is not sufficient and glow lamp on cluster blinks.
If a system is intalled, the ECM connector is grounded.
Else is opened (no wire exists).
P1593 is set when ECM is recognized as 1)4WD but CAN communication signal is not transmitted from 4WD ECU 2)2WD but CAN communication signal is transmitted from 4WD ECU. After checking if 4WD auto recognition terminal is correct for each vehicle option, if no problem is detected, check poor connection in CAN communication circuit or CAN communication problem of 4WD ECU.
Item
Detecting Condition
Possible Cause
DTC Strategy
Voltage monitoring
4WD recognition terminal circuit
CAN communication line circuit
4WD component failure
ECM component failure
Enable Conditions
IG KEY "ON"
Threshold value
TCM signal is not detected at A/T vehicle
TCM signal is detected at M/T vehicle
Diagnosis Time
1sec.
Fail Safe
Fuel cut
NO
-
EGR Off
Fuel Limit
MIL
OFF