DIAGNOSIS Required Special Tools: • MB991958: Scan Tool (MUT-III Sub Assembly) MB991824: V.C.I MB991827: USB Cable MB991911: Main Harness B • MD998478: Test Harness

STEP 1. Using scan tool MB991958, check data list item 22: Crankshaft Position Sensor.

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 data reading mode for item 22, Crankshaft Position Sensor. • The tachometer and engine speed indicated on the scan tool should much. (4) Turn the ignition switch to the "LOCK" (OFF) position. Q: Is the sensor 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. Using the oscilloscope, check the crankshaft position sensor. (1) Disconnect the crankshaft position sensor connector A-43 and connect the test harness special tool (MD998478) in between.

(2) Connect the oscilloscope probe to the crankshaft position sensor side connector terminal No. 2 (black clip of special tool). NOTE: When measuring with the PCM side connector, connect an oscilloscope probe to terminal No. 45. (3) Start the engine and run at idle.

(4) Check the waveform. The waveform should show a pattern similar to the illustration. (5) Turn the ignition switch to the "LOCK" (OFF) position. Q: Is the waveform normal? YES: Go to Step 3. NO: Go to Step 5.

STEP 3. Check connector A-43 at the crankshaft position sensor for damage.

Q: Is the connector in good condition? YES: Go to Step 4. NO: Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 20.

STEP 4. Using scan tool MB991958, check data list item 22: Crankshaft Position Sensor.

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) Set scan tool MB991958 to the data reading mode for item 22, Crankshaft Position Sensor. The tachometer and engine speed indicated on the scan tool should much. (4) Turn the ignition switch to the "LOCK" (OFF) position. Q: Is the sensor operating properly? 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 20.

STEP 5. Check connector A-43 at the crankshaft position sensor for damage.

Q: Is the connector in good condition? YES: Go to Step 6. NO: Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 20.

STEP 6. Measure the sensor supply voltage at crankshaft position sensor harness side connector A-43.

(1) Disconnect the connector A-43 and measure at the harness side. (2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal No. 2 and ground. Voltage should be between 4.8 and 5.2 volts (4) Turn the ignition switch to the "LOCK" (OFF) position. Q: Is the measured voltage between 4.8 and 5.2 volts? YES: Go to Step 11. NO: Go to Step 7.

STEP 7. Measure the sensor supply voltage at PCM connector C-90 by backprobing.

(1) Do not disconnect the PCM connector C-90. (2) Disconnect the crankshaft position sensor connector A-43. (3) Turn the ignition switch to the "ON" position.

(4) Measure the voltage between terminal No. 45 and ground by backprobing. Voltage should be between 4.8 and 5.2 volts. (5) Turn the ignition switch to the "LOCK" (OFF) position. Q: Is the measured voltage between 4.8 and 5.2 volts? YES: Go to Step 8. NO: Go to Step 9.

STEP 8. Check connector C-90 at PCM for damage.

Q: Is the connector in good condition? YES: Repair it because of open circuit between crankshaft position sensor connector A-43 (terminal No. 2) and PCM connector C-90 (terminal No. 45). Then go to Step 20. NO: Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 20.

STEP 9. Check connector C-90 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 20.

STEP 10. Check for short circuit to ground between crankshaft position sensor connector A-43 (terminal No. 2) and PCM connector C-90 (terminal No. 45).

Q: Is the harness wire in good condition? YES: Replace the PCM. Then go to Step 20. NO: Repair it. Then go to Step 20.

STEP 11. Measure the power supply voltage at crankshaft position sensor harness side connector A-43.

(1) Disconnect the connector A-43 and measure at the harness side. (2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal No. 3 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 13. NO: Go to Step 12.

STEP 12. 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 crankshaft position sensor connector A-43 (terminal No. 3) because of open circuit or short circuit to ground. Then go to Step 20. NO: Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 20.

STEP 13. Check for continuity at crankshaft position sensor harness side connector A-43.

(1) Disconnect the connector A-43 and measure at the harness side.

(2) Check for the continuity between terminal No. 1 and ground. Should be less than 2 ohms. Q: Does continuity exist? YES: Go to Step 14. NO: Repair harness wire between crankshaft position sensor connector A-43 (terminal No. 1) and ground because of open circuit or harness damage. Then go to Step 20.

STEP 14. Check connector C-59 at the MFI relay for damage.

Q: Is the harness connector in good condition? YES: Go to Step 15. NO: Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 20.

STEP 15. Check connector C-90 at PCM for damage.

Q: Is the connector in good condition? YES: Go to Step 16. NO: Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 20.

STEP 16. Check for harness damage between MFI relay connector C-59 (terminal No. 1) and crankshaft position sensor connector A-43 (terminal No. 3).

NOTE: Check harness after checking intermediate connector C-14. If intermediate connector is damaged, repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 20. Q: Is the harness wire in good condition? YES: Go to Step 17. NO: Repair it. Then go to Step 20.

STEP 17. Check for harness damage between crankshaft position sensor connector A-43 (terminal No. 2) and PCM connector C-90 (terminal No. 45).

Q: Is the harness wire in good condition? YES: Go to Step 18. NO: Repair it. Then go to Step 20.

STEP 18. Check for harness damage between crankshaft position sensor connector A-43 (terminal No. 1) and ground.

Q: Is the harness wire in good condition? YES: Go to Step 19. NO: Repair it. Then go to Step 20.

STEP 19. Check the crankshaft sensing blade. Q: Is the crankshaft sensing blade in a good condition? YES: Replace the crankshaft position sensor. Then go to Step 20. NO: Peplace the crankshaft sensing blade. Then go to Step 20.