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DTC P0606: Engine Control Module Main Processor Malfunction
 
 
 
 
ENGINE CONTROL MODULE MAIN PROCESSOR MALFUNCTION CIRCUIT
Refer to Inspection Procedure - Power Supply System and Ignition Switch-IG System .
 
 
CIRCUIT OPERATION
Refer to Inspection Procedure - Power Supply System and Ignition Switch-IG System .
 
 
TECHNICAL DESCRIPTION
The ECM check whether the microcomputer, which performs the drive control of the throttle valve and injector (high pressure), is normal.
 
 
MONITOR EXECUTION
  • Continuous
 
 
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC set in memory for the item monitored below)
  • Not applicable
Sensor (The sensor below is determined to be normal)
  • Not applicable
 
 
DTC SET CONDITIONS <Processor error>
Check Condition
  • Ignition switch is "ON" position.
Judgment Criterion
  • No surveillance pulse signals is inputted for 0.5 second.
 
 
DTC SET CONDITIONS <Direct injection driver communication error (ECM and IC)>
Logic Flow Chart
Check Condition
  • Ignition switch is "ON" position.
  • Battery positive voltage is between 10 and 16.5 volts.
Judgment Criterion
  • When communication error between the microcomputer and the direct fuel injection injector driver continues.
 
 
FAIL-SAFE AND BACKUP FUNCTION
  • Throttle opening degree position is in default position.
 
 
OBD-II DRIVE CYCLE PATTERN
  • Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 1 .
 
 
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are: )
  • MFI relay failed.
  • Shorted MFI relay circuit or connector damage.
  • Open or shorted ignition switch-IG circuit, harness damage or connector damage.
  • ECM failed.

 
 
DIAGNOSIS
STEP 1. Check the battery.
Refer to GROUP 54A, Battery - On-vehicle Service - Battery Test .
Are there any abnormalities?
Replace the battery. Then go to Step 7.
Go to Step 2.
 
STEP 2. Measure the ignition switch-IG signal voltage at ECM harness side connector.
(1) Disconnect the ECM connector and measure at the harness side.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal IGN and ground.
  • Voltage should be battery positive voltage.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is battery positive voltage (approximately 12 volts) present?
Go to Step 3.
Repair or replace the connector(s), or check and repair the harness of short to ground and open circuit in IGN line between ETACS-ECU connector and ECM connector. Then go to Step 7.
 
STEP 3. Check of harness damage in IGN line between ETACS-ECU connector and ECM connector.
Is the harness wire in good condition?
Go to Step 4.
Repair it. Then go to Step 7.
 
STEP 4. Check the MFI relay.
Refer to MFI Relay Check .
Is the measured resistance within the specified range?
Go to Step 5.
Replace the MFI relay. Then go to Step 7.
 
STEP 5. Check of short circuit to ground in C/R line between MFI relay connector and ECM connector.
Is the harness wire in good condition?
Go to Step 6.
Repair it. Then go to Step 7.
 
STEP 6. Check the trouble symptoms.
(1) Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 1 .
(2) Check the diagnostic trouble code (DTC).
Is DTC P0606 set?
Replace the ECM (Refer to Removal and Installation ). Then go to Step 7.
It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/ Inspection Service Points - How to Cope with Intermittent Malfunctions .
 
STEP 7. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 1 .
(2) Check the diagnostic trouble code (DTC).
Is DTC P0606 set?
Retry the troubleshooting.
The inspection is complete.