P0605

DTC P0605 INTERNAL CONTROL MODULE READ ONLY MEMORY ROM ERROR

Component Location:

GENERAL DESCRIPTION
An PCM ROM malfunction is detected by using a check sum technique for verifying data. Digital data is composed of zeros and ones. A check sum is the total of all ones in a string of data. By comparing the check sum value with a stored value, a malfunction can be detected. An PCM RAM malfunction is detected by writing a known string of data and comparing it with a stored string of data.

DTC DESCRIPTION
PCM sets DTC P0605 when it detects ROM with other CHECK-SUM is built into the PCM.

DTC Detecting Condition:

MONITOR DTC STATUS
This is the inspection procedure to determine whether it is present DTC or memoried one by monitoring the current signal or by using the function of oscilloscope with Hi-scan pro.
1. Connect scantool to Data Link Connector(DLC).
2. Warm up the engine to normal operating temperature.





3. Monitor the "CURRENT DATA" parameter on the scantool.
4. Is parameter displayed within specifications?

YES: Fault is intermittent caused by poor contact in the sensor's and/or PCM's connector or was repaired and PCM memory was not cleared. 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.

NO: Go to "W/Harness Inspection" procedure.

TERMINAL & CONNECTOR INSPECTION
1. 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.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination,deterioration, or damage
3. Has a problem been found?

YES: Repair as necessary and go to "Verification of vehicle Repair" procedure.

NO: Go to "Power Circuit inspection" procedure.

POWER CIRCUIT INSPECTION
1. Check for open in harness at Memory power input
1. Ignition "OFF"
2. Connect PCM connector.
3. Ignition "ON" & Engine "OFF"




4. Measure voltage between terminal 12 of PCM harness connector and chassis ground.
Specification: approximately B+

5. Is measure voltage within Specification?

YES: Go to "Component Inspection" procedure

NO:
- Open or short circuit to chassis ground between PCM harness connector and Control relay ON input circuit.
- Repair as necessary and then go to "Verification of Vehicle Repair" procedure.

COMPONENT INSPECTION
1. Check PCM
Substitute with a known-good PCM and check for proper operation. If the problem is corrected, replace PCM and then go to "Verification of Vehicle Repair" procedure.

VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1. Monitor and record the Freeze Frame Data for the Diagnostic Trouble Code (DTC) which has been diagnosed.
2. Using a Scantool, Clear the DTCs.
3. Operate the vehicle within conditions noted in the freeze frame data or enable conditions.
4. Monitor that all rediness test have been verified as "Complete"
5. Are any DTCs present?

YES: Go to the applicable troubleshooting procedure.

NO: System is performing to specification at this time.