Inspection Procedure 10
COMMENTIf all shift points are early or late while driving, the cause is probably a malfunction of the output shaft speed sensor, throttle position sensor or a solenoid valve.
TROUBLESHOOTING HINTS
The most likely causes for this case:
- Malfunction of the output shaft speed sensor
- Malfunction of the throttle position sensor
- Malfunction of each solenoid valve
- Abnormal line pressure
- Malfunction of the valve body
- Malfunction of the PCM
DIAGNOSIS
Required Special Tool: MB991502: Scan Tool (MUT-II)
CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.
STEP 1. Using Scan Tool MB991502, Check Data List Item 23: Output Shaft Speed Sensor.
1. Connect scan tool MB991502 to the data link connector.
2. Set scan tool MB991502 to the data reading mode for item 23, Output shaft speed sensor.
3. Start the engine. Move the selector lever to "3"
4. 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>.
If the result of the above check is not good (output shaft speed sensor is not operating properly), refer to Code number 23 - Output shaft speed sensor system.
If the result of the above check is good (output shaft speed sensor is operating properly), go to Step 2.
STEP 2. Using Scan Tool MB991502, Check Data List Item 11: Throttle Position Sensor.
1. Set scan tool MB991502 to the data reading mode for item 11, Throttle position sensor.
2. When the accelerator pedal is not depressed (throttle valve is fully closed), the display should be "535 to 735 mV."
3. When the accelerator pedal is depressed, the display should gradually rise.
4. When the accelerator pedal is fully depressed (throttle valve is fully open) (up to two seconds), the display should be "4,500 to 5,500 mV."
If the result of the above check is not good (throttle position sensor is not operating properly), check the throttle position sensor. Refer to diagnostic trouble code number 11, 12, 14 - Throttle Position Sensor System. Then check for the malfunction.
If the result of the above check is good (throttle position sensor is operating properly), go to Step 3.
STEP 3. Using Scan Tool MB991502, Check Data List.
1. Check the following items in the data list.
a. Item 31: Low-reverse solenoid valve duty percent
b. Item 32: Underdrive solenoid valve duty percent
c. Item 33: Second solenoid valve duty percent
d. Item 34: Overdrive solenoid valve duty percent
2. Check that the values shown are displayed when each data list item is entered.
If each solenoid valve duty percent is within specifications, go to Step 4.
If each solenoid valve duty percent is not within specifications, go to Step 6.
STEP 4. Adjust The Line Pressure.
Adjust the line pressure. Refer to Line Pressure Adjustment. Adjustments Then check the symptom. If the symptom is eliminated, diagnosis is complete. If the symptom is not eliminated, go to Step 5.
STEP 5. Disassemble And Clean The Valve Body.
Check the O-ring installation bolts for looseness and valve body for damage. Repair or replace the faulty parts. Refer to Valve Body.
If repair is not possible, replace the valve body assembly. Then check for the symptom. If the symptom is eliminated, diagnosis is complete. If the symptom is not eliminated, go to Step 7.
STEP 6. Replace Each Solenoid Valve.
Replace the faulty solenoid valve with a new one. If the symptom is eliminated, diagnosis is complete. If the symptom is not eliminated, go to Step 7.
STEP 7. Replace The PCM. Replace The PCM.
The immobilizer-ECU and the ignition key should be replaced together with it. Refer to Ignition Switch and Immobilizer System - Ignition Switch and Immobilizer System. Confirm that the malfunction symptom is eliminated. If malfunction is eliminated, diagnosis is complete.