Part 3
Speedometer does not Work (Continued)
STEP 20. Check the vehicle speed sensor connector B-39
Q: Are vehicle speed sensor connector B-39, auto-cruise control-ECU connector C-20, ECM
YES: Go to Step 21.
NO: Repair or replace it. Refer to Harness Connector Inspection. The speedometer should work normally.
STEP 21. Check the harness wires from vehicle speed sensor connector B-39
NOTE: After checking joint connector C-77 and intermediate connector C-28, check the wires. If joint connector C-77 and intermediate connector C-28 are damaged, repair or replace them. Refer to Harness Connector Inspection.
Q: Are the harness wires from vehicle speed sensor connector B-39 to auto-cruise control-ECU connector C-20, ECM
YES: Go to Step 43.
NO: Repair them. The speedometer should work normally.
STEP 22. Using scan tool MB991502, mad the A/T diagnostic trouble code.
1. Read the A/T diagnostic trouble code.
2. Turn the ignition switch to "LOCK" (OFF) position.
Q: Is A/T diagnostic trouble code number "23" output?
YES: Go to Step 29.
NO: Go to Step 23.
STEP 23. Using scan tool MB991502, check data list item 29: Vehicle Speed Signal.
1. Start the engine.
2. Set scan tool MB991502 to data reading mode for item 29: Vehicle Speed Signal.
- Check that the speedometer and scan tool display speed match when driving at a vehicle speed of 40 km/h (25 mph).
3. Turn the ignition switch to "LOCK" (OFF) position.
Q: Is the sensor operating properly?
YES: This malfunction is intermittent. Refer to How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction.
NO: Go to Step 24.
STEP 24. Using the oscilloscope, check the waveform at PCM connector C-57 <2.4L> or C-59 <3.0L>.
1. Do not disconnect connector C-57 <2.4L> or C-59 <3.0L>.
2. Connect an oscilloscope probe to PCM connector C-57 <2.4L> or C-59 <3.0L> terminal 80 by backprobing.
3. Start the engine.
4. Check the waveform.
- The waveform should show a pattern similar to the illustration when running the vehicle.
5. Turn the ignition switch to "LOCK" (OFF) position.
Q: Is the waveform normal?
YES: Go to Step 25.
NO: Go to Step 26.
STEP 25. Check connector C-57, <2.4L> or C-59 <3.0L> at PCM for damage.
Q: Is the connector in good condition?
YES: Go to step 28.
NO: Repair or replace it. Refer to Harness Connector Inspection. The speedometer should work normally.
STEP 26. Check the connector C-42 at combination meter for damage.
Q: Are the harness wires in good condition?
YES: Go to Step 27.
NO: Repair or replace it. Refer to Harness Connector Inspection. The speedometer should work normally.
STEP 27. Check harness wires between combination meter connector C-42 and PCM connector C-57 <2.4L> or C-59 <3.0L>.
NOTE: After checking, joint connector C-77 and intermediate connector C-28, check the wires If joint connector C-77 and intermediate connector C-28 are damaged, repair or replace them. Refer to Harness Connector Inspection.
Q: Is the harness wire in good condition?
YES: Go to Step 28.
NO: Repair it.
STEP 28. Using scan tool MB991502, check data list item 29: Vehicle Speed Signal.
CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.
1. Connect scan tool MB991502 to the data link connector.
2. Start the engine.
3. Set scan tool MB991502 to data reading mode for item 29, Vehicle Speed Signal.
- Check that the speedometer and scan tool display speed match when driving at a vehicle speed of 40 km/h (25 mph).
4. Turn the ignition switch to "LOCK" (OFF) position.
Q: Is the sensor operating properly?
YES: This malfunction is intermittent. Refer to How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction.
NO: Replace the PCM.
STEP 29. Using scan tool MB991502, check data list item 23: Output Shaft Speed Sensor.
1. Set scan tool MB991502 to data reading mode for item 23: Output Shaft Speed Sensor.
- When driving at constant speed of 50 km/h (31 mph), the display should be "1,600 - 1,900 r/min." <2.4L Engine>, "1,300 - 1,600 r/min." <3.0L Engine> (Gear range: 3rd gear)
2. Turn the ignition switch to "LOCK" (OFF) position.
Q: Is the sensor operating properly?
YES: This malfunction is intermittent. Refer to How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction.
NO: Go to Step 30.
STEP 30. Check the ground voltage at PCM connector C-50 <2.4L> or C-52 <3.0L> by backprobing.
1. Do not disconnect connector C-50 <2.4L> or C-52 <3.0L>.
2. Turn the ignition switch to the "ON" position.
3. Measure the voltage between terminal 16 and ground by backprobing Voltage should be 0.5 volt or less.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the voltage normal?
YES: Go to step 32.
NO: Go to Step 31.
STEP 31. Check connector C-50 <2.4L> or C-52 <3.0L> at PCM for damage.
Q: Is the connector in good condition?
YES: Go to Step 32.
NO: Repair or replace it. Refer to Harness Connector Inspection. The speedometer should work normally.
STEP 32. Check the sensor output voltage at PCM connector C-61 <2.4L> or C-63 <3.0L> by backprobing.
1. Do not disconnect connector C-61 <2.4L> or
2. Disconnect connector B-38 at the output shaft speed sensor.
3. Turn the ignition switch to "ON" position.
4. Measure the voltage between terminal 104 and ground by backprobing.
Voltage should be between 4.9 and 5.1 volts.
5. Turn the ignition switch to "LOCK" (OFF) position.
Q: Is the voltage normal?
YES: Go to step 35.
NO: Go to Step 33.
STEP 33. Check connectors C-61 <2.4L> or C-63 <3.0L> at PCM and B-38 at output shaft speed sensor for damage.
Q: Are the connectors in good condition?
YES: Go to Step 34.
NO: Repair or replace it. Refer to Harness Connector Inspection. The speedometer should work normally.
STEP 34. Check harness for short circuit to ground between PCM connector C-61 <2.4L> or C-63 <3.0L> terminal 104 and output shaft speed sensor connector B- 38 terminal 2.
Q: Is the harness wire in good condition?
YES: Go to Step 35.
NO: Repair it.
STEP 35. Using the oscilloscope, check the waveform at PCM connectors C-50, C-61, <2.4L> or C-52, C-63 <3.0L> by backprobing.
1. Do not disconnect connectors C-50, C-61 <2.4L> or C-52, C-63 <3.0L>.
2. Connect an oscilloscope probe to PCM connector C-50 <2.4L> or C-52 <3.0L> terminal 16 and to PCM connector C-61 <2.4L> or C-63 <3.0L> terminal 104 by backprobing.
3. Start the engine and run at constant speed of 50 km/h (31 mph). (Gear range: 3rd gear)
4. Check the waveform.
The 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 volts and less. The output waveform should not contain the noise.
5. Turn the ignition switch to "LOCK" (OFF) position.
Q: Is the waveform normal?
YES: Go to Step 36.
NO: Go to Step 37.
STEP 36. Check connectors C-50, C-61 <2.4L> or C-52, C-63 <3.0L> at PCM for damage.
Q: Are the connectors in good condition?
YES: Go to Step 24.
NO: Repair or replace it. Refer to Harness Connector Inspection. The speedometer should work normally.
STEP 37. Check connectors C-50, C-41 <2.4L> or C-52, C-63 <3.0L> at PCM and B-38 at output shaft speed sensor for damage.
Q: Are the connectors in good condition?
YES: Go to Step 38.
NO: Repair or replace it. Refer to Harness Connector Inspection. The speedometer should work normally.
STEP 38. Check the continuity at output shaft speed sensor connector B-38.
1. Disconnect connector B-38 and measure at the harness side.
2. Check for the continuity between terminal 1 and ground.
- Should be less than 2 Ohm.
Q: Is the continuity normal?
YES: Go to Step 39.
NO: Go to Step 41.
STEP 39. Check the sensor output voltage at output shaft speed sensor connector B-38.
1. Disconnect connector B-38 and measure at the harness side.
2. Turn the ignition switch to "ON" position.
3. Measure the voltage between terminal 2 and ground. Voltage should be between 4.9 and 5.1 volts.
4. Turn the ignition switch to "LOCK" (OFF) position..
Q: Is the voltage normal?
YES: Go to Step 40.
NO: Repair it because of harness open circuit between output shaft speed sensor connector B-38 terminal 2 and PCM connector C-61 <2.4L-A/T>, C-63 <3.0L-A/T> terminal 104.
STEP 40. Check the power supply voltage at output shaft speed sensor connector B-38.
1. Disconnect connector B-38 and measure at the harness side.
2. Turn the ignition switch to "ON" position.
3. Measure the voltage between terminal 3 and ground. Voltage should be battery positive voltage.
4. Turn the ignition switch to "LOCK" (OFF) position.
Q: Is the voltage normal?
YES: Go to Step 43.
NO: Go to Step 41.
STEP 41. Check connectors C-50, C-61 <2.4L> or C-52, C-63 <3.0L> at PCM for damage.
Q: Are the connectors in good condition?
YES: Go to Step 42.
NO: Repair or replace it Refer to Harness Connector Inspection. The speedometer should work normally.
STEP 42. Check harness wires between PCM connectors C-50, C-61 <2.4L> or C-52, C-63 <3.0L> and junction block connector C-111.
NOTE: After checking, intermediate connector C-28 and junction block C-111, C-112 check the wires. if intermediate connector C-28 and junction block C-111, C-112 are damaged, repair or replace them. Refer to Harness Connector Inspection.
Q: Are harness wires between the PCM connectors C-50, C-61 <2.4L> or C-52, C-63 <3.0L> and junction block connector C-111 in good condition?
YES: Go to Step 43.
NO: Repair or replace it. Refer to Harness Connector Inspection. The speedometer should work normally.
STEP 43. Check each equipment.
Disconnect auto-cruise control-ECU connector C-20 and combination meter connector C-42 in that order one by one. Then check that MFI system DTC P0500 does not reset under any conditions.
CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.
1. Connect scan tool to the data link connector.
2. Turn the ignition switch to "ON" position.
3. Read the MFI system diagnostic trouble code.
Q: Does MFI system DTC P0500 reset when one of auto-cruise control-ECU or combination meter, ECM or PCM is disconnected?
YES: Go to Step 44.
NO: Replace the auto-cruise control-ECU, combination meter or ECM
STEP 44. Recheck for malfunction.
Q: Is a malfunction eliminated?
YES: This diagnosis is complete. (If no malfunctions are not found in all steps, an intermittent malfunction is suspected. Refer to How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction.)
NO: Replace the speedometer