3.
Has a problem been found?
Repair as necessary and go to "Verification of Vehicle Repair" procedure.
Go to "Component Inspection" procedure.
The ECM function switches valid for the whole driving cycle are selected in the initialization of the background test and are made available in the corresponding messages.
An ECM ROM malfunction is detected by using a checksum technique for verifying data.
Digital data is composed of zeros and ones. A checksum is the total of all ones in a string of data.
By comparing the checksum value with a stored value, a malfunction can be detected.
In case of the EEPROM error, the engine symptoms will occur the running engine stall and the starting impossible.
If the ECM is generated threshold value, the ECM judged this as a fault and DTC is set.
Item | Detecting Condition | Possible Cause |
DTC Strategy | ● ECM check | ● Faulty ECM |
Enable Conditions | ● Ignition on | |
Threshold Value | ● Case 1:EEPROM - communication error ● Case 2:EEPROM - calibration error ● Case 3:EEPROM - code word is incorrect or missing | |
Diagnostic Time | ● Case 1: 0 sec ● Case 2: 0 sec ● Case 3: 0 sec | |
MIL Fuel Limit Fuel Cut EGR Off | ● Yes ● Yes ● No ● No |
Many malfunctions in the electrical system are caused by poor harness and terminals.
Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
Has a problem been found?
Repair as necessary and go to "Verification of Vehicle Repair" procedure.
Go to "Component Inspection" procedure.
Check ECM.
Ignition "OFF" & Engine "OFF".
Disconnect ECM from vehicle.
Substitute with a known-good ECM and check for proper operation.
Is the problem corrected?
▶ Replace ECM and then go to "Verification of Vehicle Repair" procedure.
▶ Thoroughly check connectors for looseness, poor connection,bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.
After a repair, it is essential to verify that the fault has been corrected.
Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode and then clear DTC.
Operate the vehicle within DTC Enable conditions in General information.
Are any DTCs present ?
Go to the applicable troubleshooting procedure.
System is performing to specification at this time.
