4.
Read "DTC Status" parameter.
A malfunction is detected by using a checksum technique for verifying data. The 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.
The ECM monitors RAM areas and communication connections between microcontroller and output drivers and sets DTC P0605 if failure is detected.
ITEM | DETECTING CONDITION | POSSIBLE CAUSE |
DTC Strategy | ● Check RAM Area / Communication connections | ● Contact resistance in connectors ● Faulty ECM |
Enable Conditions | ● Ignition ON | |
Threshold Value | ● Internal check | |
Diagnostic Time | ● 0.1 sec. |
Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode.
Press F4(DTAL) to select DTC information from the DTCs menu.
Confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions
Read "DTC Status" parameter.
Is parameter displayed "History(Not Present) fault"?
History (Not Present) fault : DTC occurred but has been cleared.
Present fault : DTC is occurring at present time.
▶ Fault is intermittent caused by poor contact in the sensor's and/or ECM's connector or was repaired and ECM memory was not cleared. Thoroughly check connectors for loose or poor connections, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.
▶ Go to next step as below.
Ignition "OFF".
Disconnect ECM connector.
Turn ignition "ON" and measure voltage between terminal 7 of the ECM harness connector and chassis ground
Specification : Remain stable at battery voltage
Are circuits remaining stable at battery voltage?
▶ Test with a new ECM and check for proper operation. If problem is corrected, replace ECM and go to "Verification of Vehicle Repair" procedure.
▶ If voltage fluctuates, check circuit Thoroughly for loose, bent or corroded terminals, Repair as necessary and 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.
Press F4(DTAL) and confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions.
Read "DTC Status" parameter.
Is parameter displayed "History(Not Present) fault"?
▶ System performing to specification at this time. Clear the DTC
▶ Go to the applicable troubleshooting procedure.
