DIAGNOSIS Required Special Tools: • MB991958: Scan Tool (MUT-III Sub Assembly) MB991824: V.C.I MB991827: USB Cable MB991911: Main Harness B • MD998474: Test Harness

STEP 1. Using scan tool MB991958, check actuator test items 01, 02, 03, 04, 05, 06: Injectors.

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) Start the engine and run at idle. (3) Set scan tool MB991958 to the actuator testing mode for item 01, 02, 03, 04, 05, 06 Injectors. (4) Warm up the engine to normal operating temperature: 80°C to 96°C (176°F to 205°F). • Does the idle state worsen when the injector is cut off. (Does idling become unstable or does the engine stall) (5) Turn the ignition switch to the "LOCK" (OFF) position. Q: Is the actuator operating properly? YES: It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points . NO: Go to Step 2.

STEP 2. Check connector A-04 at injector intermediate connector for damage.

Q: Is the connector in good condition? YES: Go to Step 3. NO: Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 12.

STEP 3. Check the injector resistance at injector intermediate connector A-04.

(1) Disconnect the injector intermediate connector A-04.

(2) Measure the resistance between each male connector side terminal. a.Measure the resistance between terminal No. 3 and No. 8 when measuring No. 1 cylinder. b.Measure the resistance between terminal No. 2 and No. 8 when measuring No. 2 cylinder. c.Measure the resistance between terminal No. 1 and No. 8 when measuring No. 3 cylinder. d.Measure the resistance between terminal No. 7 and No. 8 when measuring No. 4 cylinder. e.Measure the resistance between terminal No. 6 and No. 8 when measuring No. 5 cylinder. f.Measure the resistance between terminal No. 5 and No. 8 when measuring No. 6 cylinder. • Resistance should be between 13 and 16 ohms. Q: Is the measured resistance between 13 and 16 ohms? YES: Go to Step 6. NO: Go to Step 4.

STEP 4. Check the connector at injector for damage.

(1) Remove the intake manifold. a.Check the connector A-75 when checking No. 1 cylinder. b.Check the connector A-72 when checking No. 2 cylinder. c.Check the connector A-74 when checking No. 3 cylinder. d.Check the connector A-71 when checking No. 4 cylinder. e.Check the connector A-73 when checking No. 5 cylinder. f.Check the connector A-70 when checking No. 6 cylinder. Q: Is the harness connector in good condition? YES: Go to Step 5. NO: Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 12.

STEP 5. Check the injector.

(1) Disconnect the injector connector A-75 <No. 1 cylinder> or A-72 <No. 2 cylinder> or A-74 <No. 3 cylinder> or A-71 <No. 4 cylinder> or A-73 <No. 5 cylinder> or A-70 <No. 6 cylinder>.

(2) Measure the resistance between injector side connector terminal No. 1 and No. 2. Standard value: 13 - 16 ohms [at 20°C (68°F)] Q: Is the resistance between 13 and 16 ohms [at 20°C (68°F)]? YES: Repair harness wire between injector intermediate connector and injector connector because of open circuit or short circuit to ground or harness damage. a.Repair harness wire between injector intermediate connector A-04 (terminal No. 8) and injector connector A-75 (terminal No. 1) and harness wire between injector connector A-75 (terminal No. 2) and injector intermediate connector A-04 (terminal No. 3) when checking No. 1 cylinder. b.Repair harness wire between injector intermediate connector A-04 (terminal No. 8) and injector connector A-72 (terminal No. 1) and harness wire between injector connector A-72 (terminal No. 2) and injector intermediate connector A-04 (terminal No. 2) when checking No. 2 cylinder. c.Repair harness wire between injector intermediate connector A-04 (terminal No. 8) and injector connector A-74 (terminal No. 1) and harness wire between injector connector A-74 (terminal No. 2) and injector intermediate connector A-04 (terminal No. 1) when checking No. 3 cylinder. d.Repair harness wire between injector intermediate connector A-04 (terminal No. 8) and injector connector A-71 (terminal No. 1) and harness wire between injector connector A-71 (terminal No. 2) and injector intermediate connector A-04 (terminal No. 7) when checking No. 4 cylinder. e.Repair harness wire between injector intermediate connector A-04 (terminal No. 8) and injector connector A-73 (terminal No. 1) and harness wire between injector connector A-73 (terminal No. 2) and injector intermediate connector A-04 (terminal No. 6) when checking No. 5 cylinder. f.Repair harness wire between injector intermediate connector A-04 (terminal No. 8) and injector connector A-70 (terminal No. 1) and harness wire between injector connector A-70 (terminal No. 2) and injector intermediate connector A-04 (terminal No. 5) when checking No. 6 cylinder. • Then go to Step 12. NO: Replace the injector. Then go to Step 12.

STEP 6. Measure the power supply voltage at injector intermediate connector A-04.

(1) Disconnect the connector A-04 and measure at the female connector side. (2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal No. 8 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? YES: Go to Step 8. NO: Go to Step 7.

STEP 7. Check connector C-59 at MFI relay for damage.

Q: Is the connector in good condition? YES: Check connector C-14 at intermediate connector for damage, and repair or replace as required. Refer to GROUP 00E, Harness Connector Inspection . If intermediate connector is in good condition, repair harness wire between MFI relay connector C-59 (terminal No. 1) and injector intermediate connector A-04 (terminal No. 8) because of open circuit or short circuit to ground. Then go to Step 12. NO: Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 12.

STEP 8. Check for harness damage between MFI relay connector C-59 (terminal No. 1) and injector intermediate connector A-04 (terminal No. 8).

Q: Is the harness wire in good condition? YES: Go to Step 9. NO: Repair it. Then go to Step 12.

STEP 9. Check connector C-89 at PCM for damage.

Q: Is the connector in good condition? YES: Go to Step 10. NO: Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 12.

STEP 10. Check for open circuit and short circuit to ground and harness damage between injector intermediate connector and PCM connector.

a.Check the harness wire between intermediate connector A-04 (terminal No. 3) and PCM connector C-89 (terminal No. 1) when checking No. 1 cylinder. b.Check the harness wire between intermediate connector A-04 (terminal No. 2) and PCM connector C-89 (terminal No. 9) when checking No. 2 cylinder. c.Check the harness wire between intermediate connector A-04 (terminal No. 1) and PCM connector C-89 (terminal No. 24) when checking No. 3 cylinder. d.Check the harness wire between intermediate connector A-04 (terminal No.7) and PCM connector C-89 (terminal No. 2) when checking No. 4 cylinder. e.Check the harness wire between intermediate connector A-04 (terminal No. 6) and PCM connector C-89 (terminal No. 10) when checking No. 5 cylinder. f.Check the harness wire between intermediate connector A-04 (terminal No. 5) and PCM connector C-89 (terminal No. 25) when checking No. 6 cylinder. Q: Is the harness wire in good condition? YES: Go to Step 11. NO: Repair it. Then go to Step 12.

STEP 11. Using the oscilloscope, check the injector. (1) Disconnect the injector intermediate connector A-04 and connect the test harness special tool (MD998474) in between.

(2) Connect the oscilloscope probe to each injector intermediate connector terminal to oscilloscope each cylinder: • Terminal No. 3 (green clip of the special tool) when checking No. 1 cylinder. • Terminal No. 2 (white clip of the special tool) when checking No. 2 cylinder. • Terminal No. 1 (blue clip of the special tool) when checking No. 3 cylinder. • Terminal No. 7 (yellow clip of the special tool) when checking No. 4 cylinder. • Terminal No. 6 (red clip of the special tool) when checking No. 5 cylinder. • Terminal No. 5 (black clip of the special tool) when checking No. 6 cylinder. NOTE: When measuring with the PCM side connector, connect an oscilloscope probe to the each of the following terminals. • PCM terminal No. 1 when checking No. 1 cylinder injector • PCM terminal No. 9 when checking No. 2 cylinder injector • PCM terminal No. 24 when checking No. 3 cylinder injector • PCM terminal No. 2 when checking No. 4 cylinder injector • PCM terminal No. 10 when checking No. 5 cylinder injector • PCM terminal No. 25 when checking No. 6 cylinder injector (3) Start the engine and run at idle.

(4) Measure the waveform. • The waveform should show a normal pattern similar to the illustration. (5) Turn the ignition switch to the "LOCK" (OFF) position. Q: Is the waveform normal? YES: It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points . NO: Replace the PCM. Then go to Step 12.