P0604

DTC P0604: 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 Tools:

- 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)Read the DTC.
(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is DTC P0604 set?

YES Replace the ECM (Refer to, Removal and Installation Removal and Replacement).

NO It can be assumed that this malfunction is intermittent. How to Cope With Intermittent Malfunctions.