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Home >> Mitsubishi Truck >> 2000 >> Montero Sport LS 2WD V6-3.0L SOHC >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> Manufacturer Code Charts >> Transmission Control System >> DTC 23

DTC 23









CIRCUIT OPERATION
- A coil built into the output shaft speed sensor generates 0 - 5 volts pulse signal at both ends of this coil when the output shaft rotates. The pulse signal frequency increases with a rise in output shaft speed.
- Both ends of the coil are connected to the PCM (terminals 57 and 104) via the output shaft speed sensor connector (terminals 1 and 2). The PCM detects the output shaft speed by the signal input to terminal (terminal 104).
- The output shaft speed sensor generates the pulse signal as the teeth of the transfer drive gear pass the magnetic tip of the sensor.

DTC SET CONDITIONS
- If the output from the output shaft speed sensor is continuously 50 percent lower than the vehicle speed for one second or more while driving in 3rd or 4th gear at a speed of 30 km/h (19 mph) or more, it is judged to be an open circuit or short-circuit in the output shaft speed sensor and diagnostic trouble code number "23" is output. If diagnostic trouble code number "23" is output four times, the transmission is locked into 3rd gear or 2nd gear as a fail-safe measure, and the "N" range light flashes at a frequency of 1 Hz.

TROUBLESHOOTING HINTS
The most likely causes for this code to be set:
- Malfunction of the output shaft speed sensor
- Malfunction of the output shaft
- Damaged connector
- Malfunction of the PCM

DIAGNOSIS





Required Special Tool: MB991502: Scan Tool (MUT-II)

CAUTION: To prevent damage to the scan tool MB991502, make sure the ignition switch is "OFF" before connecting or disconnecting the scan tool MB991502.

STEP 1. Using scan tool MB991502, check data list item 23: Output shaft speed sensor.
1. Start the engine. Selector lever position is "3."
2. When driving at constant speed of 50 km/h (31 mph), the display should be "1,500 - 1,800 r/min." <3.0L Engine>, "1,400 - 1,700 r/min." <3.5L Engine>
If the output shaft speed sensor is operating properly, this malfunction can be intermittent. Refer to How to Use Troubleshooting/inspection Service Points.
If the output shaft speed sensor is not operating properly, go to Step 2.

STEP 2. Check the power supply circuit at the output shaft speed sensor.





1. Disconnect harness connector B-15 and measure at the harness side.
2. Turn the ignition switch "ON."
3. Measure the voltage between terminal 3 and ground.
- Voltage should be system voltage.
If system voltage, go to Step 3.
If not system voltage, go to Step 7.

STEP 3. Check the signal circuit at the output shaft speed sensor.





1. Disconnect harness connector B-15 and measure at the harness side.
2. Turn the ignition switch "ON."
3. Measure voltage between terminal 2 and ground.
- Voltage should be approximately 5 volts.
If 5 volts, go to Step 4.
If not 5 volts, go to Step 8.

STEP 4. Check the ground circuit at the output shaft speed sensor.





1. Disconnect harness connector B-15 and measure at the harness side.
2. Turn the ignition switch "OFF."
3. Check for continuity between terminal 1 and ground.
- There should be continuity (0 Ohms).
If continuity, go to Step 5.
If no continuity, go to Step 8.

STEP 5. Using an oscilloscope, check the output shaft speed sensor.
Required Special Tool: MB991709: Test Harness





1. Disconnect input shaft speed sensor connector B-16, and connect special tool MB991709 in between.
2. Connect an oscilloscope probe to input shaft speed sensor connector B-16 (terminal 2).
3. Start the engine and run it at 1,500 - 1,800 r/min <3.0L Engine>, 1,400 - 1,700 r/min <3.5L Engine> [approximately 50 km/h (31 mph)]. Selector lever position should be "W"





4. Check the waveform.
- The waveform should show a normal pattern as shown in the illustration.
5. Turn off the engine.
If the waveform shows a normal pattern, check the malfunction. If the malfunction is not eliminated, replace the PCM.
If the waveform does not show a normal pattern, go to Step 6.

STEP 6. Replace the output shaft speed sensor. Then check the malfunction.





Replace the output shaft speed sensor. Recheck for DTCs.
If a malfunction is eliminated, diagnosis is completed.
If the malfunction is not eliminated, go to Step 13.

STEP 7. Check harness connector B-15 at the output shaft speed sensor for damage.





If the harness connector B-15 is damaged, repair or replace it. Refer to Harness Connector Inspection. Recheck for DTCs.
If harness connector B-15 is in good condition, go to Step 8.

STEP 8. Check harness connector D-08 at the junction block for damage.





If harness connector D-08 is damaged, repair or replace it. Refer to Harness Connector Inspection. Recheck for DTCs.
It harness connector D-08 is in good condition, go to Step 9.

STEP 9. Check the harness wires between junction block connector D-08 and output shaft speed sensor connector B-15.





NOTE: After inspecting intermediate connectors C-30 and D-13, inspect the wire. If intermediate connectors C-30 and D-13 are damaged, repair or replace them. Refer to Harness Connector Inspection.





If any harness wires between junction block connector D-08 and output shaft speed sensor connector B-15 are damaged, repair them. Refer to Harness Connector Inspection. Recheck for DTCs.
If the harness wires are in good condition, recheck for DTCs.
If the malfunction is not eliminated, check the power distribution. Refer to Power Distribution. After check, check the malfunction.

STEP 10. Check harness connector B-15 at the output shaft speed sensor for damage.





If harness connector B-15 is damaged, repair or replace it. Refer to Harness Connector Inspection. Recheck for DTCs.
If harness connector B-15 is in good condition, go to Step 11.

STEP 11. Check harness connectors C-90 and C-92 at the PCM for damage.





If harness connectors C-90 and C-92 are damaged, repair or replace them. Refer to Harness Connector Inspection. Recheck for DTCs.
If harness connectors C-90 and C-92 are in good condition, go to Step 12.

STEP 12. Check the harness wires between PCM connectors C-90 and C-92 and output shaft speed sensor connector B-15.





NOTE: After inspecting intermediate connector C-96 and joint connector C-71, inspect the wire. If intermediate connector C-96 and joint connector C-71 are damaged, repair or replace them. Refer to Harness Connector Inspection.

If any harness wires between PCM connectors C-90 and C-92 and output shaft speed sensor connector B-15 are damaged, repair them. Refer to Harness Connector Inspection. Recheck for DTCs.
If the harness wires are in good condition, recheck for DTCs.
If the malfunction is not eliminated, replace the PCM.

STEP 13. Check the output shaft.





If the output shaft is not defective, go to Step 14.
If the output shaft is defective, replace the output shaft. Recheck for DTCs.

STEP 14. Recheck for DTCs.
If the malfunction is eliminated, diagnosis is complete.
If the malfunction is not eliminated, eliminate the source of the noise.


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