DTC P0606: Engine Control Module Main Processor Malfunction

ENGINE CONTROL MODULE MAIN PROCESSOR MALFUNCTION

Refer to Inspection Procedure 21 - Power Supply System and Ignition Switch - IG System .

CIRCUIT OPERATION

Refer to Inspection Procedure 21 - Power Supply System and Ignition Switch - IG System .

TECHNICAL DESCRIPTION

Throttle actuator control processor checks the ECM for abnormal conditions.

DESCRIPTIONS OF MONITOR METHODS

MONITOR EXECUTION

MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)

Other Monitor (There is no temporary DTC stored in memory for the item monitored below)

Not applicable

Sensor (The sensor below is determined to be normal)

Not applicable

DTC SET CONDITIONS

Check Condition

Ignition switch is "ON" position.

Judgement Criterion

No surveillance pulse signals should be input for 0.5 second.

OBD-II DRIVE CYCLE PATTERN

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

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. Check the battery.

Refer to GROUP 54A, Battery - On-vehicle Service - Battery Test

Q. Are there any abnormalities?

	Replace the battery. Then go to Step 11.

	Go to Step 2.

STEP 2. Check harness connector B-109 at ECM for damage.

Q. Is the harness connector in good condition?

	Go to Step 3.

	Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 11.

STEP 3. Measure the ignition switch-IG signal voltage at ECM harness side connector B-109.

(1)Disconnect the connector B-109 and measure at the harness side.

(2)Turn the ignition switch to the "ON" position.

(3)Measure the voltage between terminal No. 92 and ground.

Voltage should be battery positive voltage.

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

Q. Is battery positive voltage (approximately 12 volts) present?

Go to Step 5.

Go to Step 4.

STEP 4. Check harness connector C-304 at ETACS-ECU for damage.

Q. Is the harness connector in good condition?

	Repair harness wire between ETACS-ECU connector C-304 (terminal No. 10) and ECM connector B-109 (terminal No. 92) because of open circuit or short circuit to ground. Then go to Step 11.

	Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 11.

STEP 5. Check harness connector C-304 at ETACS-ECU for damage.

Q. Is the harness connector in good condition?

	Go to Step 6.

	Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 11.

STEP 6. Check for harness damage between ETACS-ECU connector C-304 (terminal No. 10) and ECM connector B-109 (terminal No. 92).

Q. Is the harness wire in good condition?

	Go to Step 7.

	Repair it. Then go to Step 11.

STEP 7. Check harness connector A-30X at MFI relay for damage.

Q. Is the harness connector in good condition?

	Go to Step 8.

	Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 11.

STEP 8. Check the MFI relay.

(1)Remove the MFI relay.

(2)Check for continuity between the MFI relay terminals No. 1 and No. 3.

There should be continuity.

(3)Use jumper wires to connect MFI relay terminal No. 3 to the positive battery terminal and terminal No. 1 to the negative battery terminal.
(4)Check for continuity between the MFI relay terminals No. 4 and No. 2 while connecting and disconnecting the jumper wire at the negative battery terminal.

Continuity (2 ohms or less) <Negative battery terminal connected>
Should be open loop <Negative battery terminal disconnected>

(5)Install the MFI relay.

Q. Is the measured resistance within the specified range?

Go to Step 9.

Replace the MFI relay. Then go to Step 11.

STEP 9. Check for short circuit to ground between MFI relay connector A-30X (terminal No. 1) and ECM connector B-109 (terminal No. 73).

Q. Is the harness wire in good condition?

	Go to Step 10.

	Repair it. Then go to Step 11.

STEP 10. 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 P0606 set?

Replace the ECM. When the ECM is replaced, register the ID code. Refer to GROUP 42B, Diagnosis - ID Code Registration Necessity Judgment Table <Vehicles with KOS>

or GROUP 42C, Diagnosis - ID Codes Registration Judgment Table <Vehicles with WCM>

. Then go to Step 11.

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 11. 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.

Q. Is DTC P0606 set?

Retry the troubleshooting.

The inspection is complete.