Inspection Procedure 7

COMMENT
If abnormal shocks or delay of two seconds or more occur when the selector lever is shifted from "N" to "R" range while the engine is idling, the cause is probably abnormal reverse clutch pressure or low-reverse brake pressure, or a malfunction of the reverse clutch, low-reverse brake, valve body or throttle position sensor.

TROUBLESHOOTING HINTS
The most likely causes for this case:
- Abnormal reverse clutch pressure
- Abnormal low-reverse brake pressure
- Malfunction of the low-reverse solenoid valve
- Malfunction of the reverse clutch
- Malfunction of the low-reverse brake
- Malfunction of the valve body
- Malfunction of the throttle position sensor
- Malfunction of the PCM

DIAGNOSIS





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

CAUTION: To prevent damage to scan tool MB9911502, always turn the ignition switch to "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.

STEP 1. Using Scan Tool MB991502, Carry Out The Actuator Test.
1. Connect scan tool MB991502 to the data link connector.
2. Check the following item in the actuator test. Refer to Actuator Test Reference Table.
a. Item 1: Low-reverse solenoid valve
3. Check that the solenoid valve clicks.
If the solenoid clicks, go to Step 2.
If the clicks cannot be heard, repair or replace the low-reverse solenoid valve. Refer to Valve Body. Then confirm that the symptom is eliminated.

STEP 2. Check When Shift Shocks Occur.
If shift shocks occur when engaging from "N" to "R," go to Step 3.
If shift shocks occur when the vehicle starts moving, go to Step 7.

STEP 3. Check The Hydraulic Pressure (For Reverse Clutch).
Measure the hydraulic pressure for reverse clutch when the selector lever is at the "R" range, and check if the hydraulic pressure is within the standard value. Refer to Hydraulic Pressure Test. Hydraulic Pressure Tests
If within the standard value, go to Step 4.
If not within the standard value, go to Step 9.

STEP 4. Check The Hydraulic Pressure (For Low-Reverse Brake).
Measure the hydraulic pressure for low-reverse brake when the selector lever is at the "R" range, and check if the hydraulic pressure is within the standard value. Refer to Hydraulic Pressure Test. Hydraulic Pressure Tests
If within the standard value, go to Step 5.
If not within the standard value, go to Step 9.

STEP 5. Check The Reverse Clutch System And Low-Reverse Brake System.





1. Remove the valve body cover and valve body.
2. Blow compressed air into the reverse clutch oil orifice of the transaxle case. Then check if the reverse clutch piston moves and air pressures are maintained in that condition. Repeat for the low-reverse brake.
If both air pressures are maintained, go to Step 6.
If both air pressures or either of the air pressures are not maintained, go to Step 9.

STEP 6. Check The Reverse Clutch And Low-Reverse Brake.





Remove the transaxle assembly.
Check the facing for seizure and the piston seal ring for damage and interference with the retainer. Repair or replace the faulty parts. Refer to Reverse and Overdrive Clutch. Then check for the symptom.
If the symptom is eliminated, diagnosis is complete.
If the symptom is not eliminated, go to Step 10.

STEP 7. Do Shift Shocks Occur Sometimes?
If yes, go to Step 8.
If no, go to Step 9.

STEP 8. 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 the symptom.
If the result of the above check is good (throttle position sensor is operating properly), go to Step 9.

STEP 9. Disassemble And Clean The Valve Body.





Check the O-ring installation bolts for looseness and the 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 the symptom.
If the symptom is eliminated, diagnosis is complete.
If the symptom is not eliminated, go to Step 10.

STEP 10. 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.