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 after cranking the engine for at least 2 sec.
(3) Read the DTC.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is any DTC set?
Refer to, Diagnostic Trouble Code Chart . Go to Step 2.
STEP 2. Check harness connector B-101, B-102, B-105 and B-106 at injector for damage.
STEP 3. Check the injector.
(1) Disconnect the injector connectors B-101, B-102, B-105 and B-106.
(2) Measure the resistance between each injector side connector terminal No. 1 and No. 2.Standard value: 10.5 - 13.5 Ω [at 20°C (68°F)]
Is the measured resistance between 10.5 and 13.5 Ω [at 20°C (68°F)]?
Go to Step 4. Replace the faulty injector. Then confirm that the malfunction symptom is eliminated.
STEP 4. Measure the power supply voltage at injector harness side connector.
(1) Disconnect the connectors B-101, B-102, B-105 and B-106 and measure at the harness side.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal No. 1 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 14. Go to Step 5.
STEP 5. Check harness connector A-70X at injector relay for damage.
STEP 6. Check the injector relay.
(1) Remove the injector relay.
(2) Check for continuity between the injector relay terminal No. 1 and No. 2.- There should be continuity.
(3) Use jumper wires to connect injector relay terminal No. 1 to the positive battery terminal and terminal No. 2 to the negative battery terminal.
(4) Check for continuity between the injector relay terminal No. 3 and No. 4 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 injector relay.
Is the measured resistance normal?
Go to Step 7. Replace the injector relay. Then confirm that the malfunction symptom is eliminated.
STEP 7. Check the continuity at injector relay harness side connector A-70X.
(1) Disconnect the connector A-70X and measure at the harness side.
(2) Check for the continuity between terminal No. 2 and ground.- Continuity (2 ohms or less).
Does continuity exist?
Go to Step 8. Repair harness wire between injector relay connector A-70X (terminal No. 2) and ground because of open circuit or harness damage. Then confirm that the malfunction symptom is eliminated.
STEP 8. Measure the power supply voltage at injector relay harness side connector A-70X.
(1) Disconnect the connector A-70X and measure at the harness side.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal No. 1 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 10. Go to Step 9.
STEP 9. Check harness connector C-403 at ETACS-ECU for damage.
STEP 10. Measure the power supply voltage at injector relay harness side connector A-70X.
(1) Disconnect the connector A-70X and measure at the harness side.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal No. 4 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 12. Go to Step 11.
STEP 11. Check harness connector A-37X at MFI relay for damage.
STEP 12. Check for open circuit and short circuit to ground between injector relay connector and injector connector.
STEP 13. Check harness connector C-403 at ETACS-ECU for damage.
STEP 14. Check harness connector A-37X at MFI relay and harness connector A-70X at injector relay for damage.
STEP 15. Check for harness damage between MFI relay connector A-37X (terminal No. 2) and injector relay connector A-70X (terminal No. 4).
STEP 16. Check for harness damage between injector relay connector and injector connector.
STEP 17. Using scan tool MB991958, check data list.
(1) Turn the ignition switch to the "ON" position.
(2) Check the following item in the data list. Refer to Data List Reference Table .- Item 1: Power Supply Voltage
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Are they operating properly?
Go to Step 18. Repair or replace it. Then confirm that the malfunction symptom is eliminated.
STEP 18. Using scan tool MB991958, check actuator test.
(1) Turn the ignition switch to the "ON" position.
(2) Check the following item in the actuator test. Refer to Actuator Test Reference Table . (3) Turn the ignition switch to the "LOCK" (OFF) position.
Is the actuator operating properly?
Go to Step 19. Repair or replace it. Then confirm that the malfunction symptom is eliminated.
STEP 19. Check the ignition system.
(1) Connect the timing light to terminal No. 3 of the ignition coil connectors B-21, B-22, B-23 or B-24 in order.
(2) Crank the engine.- The timing light flashes.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Does the timing light flash?
Go to Step 20. Refer to Inspection Procedure 25 - Ignition Circuit System .
STEP 20. Check the spark plugs.
STEP 21. Check the ignition coil.
STEP 22. Check the compression pressure.
STEP 23. Check the ignition timing.