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

STEP 1. Using scan tool MB991958, check data list item 22: Input Shaft Speed 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. (3) Set scan tool MB991958 to data reading mode. Item 22: Input Shaft Speed Sensor. When driving at constant speed of 50 km/h (31 mph), the display should be "1,400 - 1,700 r/min" (Gear range: 3rd gear). (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 - How to Cope with Intermittent Malfunction . NO: Go to Step 2 .

STEP 2. Measure the power supply voltage at input shaft speed sensor connector B-16.

(1) Disconnect connector B-16 and measure at the harness side. (2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal 3 and ground. The voltage should measure battery positive voltage. (4) Turn the ignition switch to the "LOCK" (OFF) position. Q: Is the measured voltage battery positive voltage? YES: Go to Step 5 . NO: Go to Step 3 .

STEP 3. Check intermediate connector C-30 and junction block connector D-13 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are the connectors and terminals in good condition? YES: Go to Step 4 . NO: Repair or replace the damaged components. Refer to GROUP 00E, Harness Connector Inspection .

STEP 4. Check the harness for open circuit or short circuit to ground between input shaft speed sensor connector B-16 terminal 3 and the junction block connector D-13 terminal 11.

Q: Is the harness wire in good condition? YES: Go to Step 5 . NO: Repair or replace the harness wire.

STEP 5. Measure the PCM to speed sensor output voltage at the input shaft speed sensor connector B-16.

(1) Disconnect connector B-16 from the speed sensor and measure voltage at the harness side. (2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal 2 and ground. The voltage should measure between 4.5 and 4.9 volts. (4) Turn the ignition switch to the "LOCK" (OFF) position. Q: Is the measured voltage between 4.5 and 4.9 volts? YES: Go to Step 11 . NO: Go to Step 6 .

STEP 6. Measure the PCM output voltage to the speed sensor at the PCM connector C-92 by backprobing.

(1) Do not disconnect connector C-92. (2) Disconnect connector B-16 at the input shaft speed sensor. (3) Turn the ignition switch to the "ON" position.

(4) Measure the voltage between PCM terminal 103 and ground by backprobing. The voltage should measure between 4.5 and 4.9 volts. (5) Turn the ignition switch to the "LOCK" (OFF) position. Q: Is the measured voltage between 4.5 and 4.9 volts? YES: Go to Step 7 . NO: Go to Step 9 .

STEP 7. Check input shaft speed sensor connector B-16, PCM connector C-92 and intermediate connector C-96 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are the connectors in good condition? YES: Go to Step 8 . NO: Repair or replace the damaged components. Refer to GROUP 00E, Harness Connector Inspection .

STEP 8. Check the harness for open circuit or damage between input shaft speed sensor connector B-16 terminal 2 and PCM connector C-92 terminal 103.

Q: Is the harness wire in good condition? YES: Go to Step 19 . NO: Repair or replace the harness wire.

STEP 9. Check input shaft speed sensor connector B-16, PCM connector C-92 and intermediate connector C-96 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are the connectors and terminals in good condition? YES: Go to Step 10 . NO: Repair or replace the damages components. Refer to GROUP 00E, Harness Connector Inspection .

STEP 10. Check the harness for short circuit to ground between input shaft speed sensor connector B-16 terminal 2 and PCM connector C-92 terminal 103.

Q: Is the harness wire in good condition? YES: Go to Step 11 . NO: Repair or replace the harness wire.

STEP 11. Measure the ground circuit for resistance at the input shaft speed sensor connector B-16.

(1) Disconnect connector B-16 from the speed sensor and measure at the harness side.

(2) Measure the resistance between terminal 1 and ground. The resistance should measure less than 2 ohms. Q: Is the measured resistance less than 2 ohms? YES: Go to Step 16 . NO: Go to Step 12 .

STEP 12. Measure the resistance at PCM connector C-90 by backprobing.

(1) Do not disconnect connector C-90. (2) Turn the ignition switch to the "ON" position.

(3) Measure the resistance between terminal 57 and ground by backprobing. The resistance should measure less than 2 ohms. (4) Turn the ignition switch to the "LOCK" (OFF) position. Q: Is the measured resistance less than 2 ohms? YES: Go to Step 13 . NO: Go to Step 15 .

STEP 13. Check input shaft speed sensor connector B-16, joint connector C-71, intermediate connector C-96 and PCM connector C-90 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are the connectors and terminals in good condition? YES: Go to Step 14 . NO: Repair or replace the damaged components. Refer to GROUP 00E, Harness Connector Inspection .

STEP 14. Check the harness for open circuit or damage between input shaft speed sensor harness side connector B-16 terminal 1 and PCM connector C-90 terminal 57.

Q: Is the harness wire in good condition? YES: Go to Step 16 . NO: Repair or replace the harness wire.

STEP 15. Check PCM connector C-90 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are the connector and terminals in good condition? YES: Replace the PCM. NO: Repair or replace the damaged components. Refer to GROUP 00E, Harness Connector Inspection .

STEP 16. Using an oscilloscope, check the input shaft speed sensor waveform at PCM connectors C-90 and C-92 by backprobing.

(1) Do not disconnect connectors C-90 and C-92.

(2) Connect an oscilloscope probe to PCM connector C-90 terminal 57 and to PCM connector C-92 terminal 103 by backprobing. (3) Start the engine and drive the vehicle at constant speed of 50 km/h (31 mph) (Gear range: 3rd gear).

(4) Check the input shaft speed sensor waveform. The input shaft speed sensor waveform should show a pattern similar to the illustration. The maximum value should be 4.8 volts and more and the minimum value 0.8 volt and less. The output waveform should not contain electrical noise. (5) Turn the ignition switch to the "LOCK" (OFF) position. Q: Is the waveform normal? YES: Go to Step 19 . NO: Go to Step 17 .

STEP 17. Replace the input shaft speed sensor.

(1) Replace the input shaft speed sensor. Refer to GROUP 23B, Transmission . (2) Test drive the vehicle. (3) Check for A/T diagnostic trouble code. Q: Is A/T DTC 22 set? YES: Go to Step 18 . NO: The procedure is complete.

STEP 18. Replace the reverse clutch retainer.

(1) Replace the reverse clutch retainer. Refer to GROUP 23B, Reverse and Overdrive Clutches . (2) Test drive the vehicle. (3) Check for A/T diagnostic trouble code. Q: Is A/T DTC 22 set? YES: An A/T DTC may have set due to external radio frequency interference (RFI) possibility caused by cellular phone activity, or aftermarket components installed on the vehicle. NO: The procedure is complete.