P0604

DTC P0604: Internal Control Module Random Access Memory (RAM) Error

TECHNICAL DESCRIPTION
Monitors the computation function of the ECM periodically.

DTC SET CONDITIONS

Check Condition
- Ignition switch is "ON" position.

Judgment Criterion
- All RAM data of ECM are defect.
or
- RAM data (engine) is defect.

FAIL-SAFE AND BACKUP FUNCTION
- Microcomputer is reset.
or
- Throttle opening degree position is in default position.

TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
- ECM failed.

DIAGNOSIS

Required Special Tool:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991910: Main Harness A

STEP 1. Using scan tool MB991958, read the diagnostic trouble code (DTC).







CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. After the DTC has been deleted, read the DTC again.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC P0604 set?

YES : Replace the ECM.

NO : It can be assumed that this malfunction is intermittent. Refer to How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions. Troubleshooting Contents