DTC 31: Low-Reverse Solenoid Valve System: Diagnosis

Required Special Tool:

MB991502: Scan Tool (MUT-II)

STEP 1. Using scan tool MB991502, check actuator test item 01: Low-Reverse Solenoid Valve.
CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.
1. Connect scan tool MB991502 to the data link connector.
  
  Fig 1: Connecting Scan Tool To Data Link Connector
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. Turn the ignition switch to the "ON" position.
3. Set scan tool MB991502 to actuator test mode for item 01, Low-Reverse Solenoid Valve.
  - An audible clicking or buzzing should be heard when the low-reverse solenoid valve is energized.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the solenoid valve operating properly?
1. YES: It can be assumed that this malfunction is intermittent.
2. NO: Go to Step 2.
STEP 2. Using scan tool MB991502, read the A/T diagnostic trouble code.
1. Connect scan tool MB991502 to the data link connector.
  
  Fig 2: Connecting Scan Tool To Data Link Connector
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. Turn the ignition switch to the "ON" position.
3. Check for A/T diagnostic trouble code.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC 54 set? (DTC 54 may be set along with multiple DTCs.)
1. YES: Refer to DTC 54: A/T Control Relay System .
2. NO: Go to Step 3.
STEP 3. Using scan tool MB991502, read the A/T diagnostic trouble code.
1. Connect scan tool MB991502 to the data link connector.
  
  Fig 3: Connecting Scan Tool To Data Link Connector
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. Turn the ignition switch to the "ON" position.
3. Check for A/T diagnostic trouble code.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC 36 set?
1. YES: Go to Step 8 .
2. NO: Go to Step 4.
STEP 4. Measure the low-reverse solenoid valve resistance at A/T control solenoid valve assembly connector B-15.
1. Disconnect connector B-15 and measure at the solenoid valve side.
  
  Fig 4: Disconnecting Connector B-15
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. Measure the resistance between solenoid valve assembly connector B-15 terminals 6 and 10.
  1. Resistance value: 2.7-3.4 ohm [at 20°C (68°F)]
Fig 5: Measuring Resistance Between Solenoid Valve Assembly Connector B-15 Terminals 6 & 10
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Q: Is the measured resistance 2.7-3.4 ohm [at 20°C (68°F)]?
1. YES: Go to Step 6 .
2. NO: Go to Step 5.
STEP 5. Measure the solenoid valve resistance at the low-reverse solenoid valve assembly inside the transaxle.
1. Disconnect connector B-15-5 and measure at the solenoid valve side.
  
  Fig 6: Disconnecting Connector B-15-5
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. Measure the resistance between low-reverse solenoid valve terminals 1 and 2.
  1. Resistance value: 2.7-3.4 ohm [at 20°C (68°F)]
Fig 7: Measuring Resistance Between Low-Reverse Solenoid Valve Terminals 1 & 2
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Q: Is the measured resistance 2.7-3.4 ohm [at 20°C (68°F)?
1. YES: Replace the harness wire between A/T control solenoid valve assembly connector B-15 and the solenoid valves.
2. NO: Replace the low-reverse solenoid valve. Refer to VALVE BODY .
STEP 6. Check A/T control solenoid valve assembly connector B-15 and PCM connector C-114 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Fig 8: Checking A/T Control solenoid Valve Assembly Connector B-15
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Fig 9: Checking PCM Connector C-114
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Q: Are the connectors and terminals in good condition?
1. YES: Go to Step 7.
2. NO: Repair or replace the damaged components.
STEP 7. Check the harness for an open or short circuit to ground between A/T control solenoid valve assembly connector B-15 terminal 6 and PCM connector C-114 terminal 129.

Fig 10: Checking A/T Control Solenoid Valve Assembly Connector B-15 For Open Or Short Circuit To Ground
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Fig 11: Checking PCM Connector C-114 For Open Or Short Circuit To Ground
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Q: Is the harness wire in good condition?
1. YES: Replace the PCM.
2. NO: Repair or replace the harness wire.
STEP 8. Measure the supply voltage at A/T control solenoid valve assembly connector B-15.
1. Disconnect solenoid valve assembly harness connector B-15.
  
  Fig 12: Disconnecting Solenoid Valve Assembly Harness Connector B-15
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. Turn the ignition switch to the "ON" position.
3. Measure the voltage between harness connector B-15 terminal 10 and ground.
  - The voltage should equal battery positive voltage.
  Fig 13: Measuring Voltage Between Terminal 10 & Ground
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage battery positive voltage?
1. YES: Go to Step 11 .
2. NO: Go to Step 9.
STEP 9. Check A/T control relay connector B-11X in the engine component relay box and A/T control solenoid valve assembly connector B-15 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Fig 14: Checking A/T Control Relay Connector B-11X
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Fig 15: Checking A/T Control Solenoid Valve Assembly Connector B-15
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Q: Are the connectors and terminals in good condition?
1. YES: Go to Step 10.
2. NO: Repair or replace the damaged components.
STEP 10. Check the harness for an open circuit or short circuit to ground between A/T control relay connector B-11X terminal 4 in the engine component relay box and A/T control solenoid valve assembly connector B-15 terminal 10.

Fig 16: Checking A/T Control Relay Connector B-11X For Open Or Short Circuit To Ground
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Fig 17: Checking A/T Control Solenoid Valve Assembly For Open Or Short Circuit To Ground
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Q: Is the harness wires in good condition?
1. YES: Go to Step 11.
2. NO: Repair or replace the harness wire.
STEP 11. Check A/T control solenoid valve assembly connector B-15 and PCM connector C-114 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Fig 18: Identifying B-11X
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Fig 19: Checking PCM Connector C-114
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Q: Are the connectors and terminals in good condition?
1. YES: Go to Step 12.
2. NO: Repair or replace the damaged components. .
STEP 12. Check the harness for an open or short circuit to ground between A/T control solenoid valve assembly connector B-15 (terminals 6 and 7) and PCM connector C-114 (terminals 107 and 129).

Fig 20: Checking A/T Control Solenoid Valve Assembly Connector B-15 For Open Or Short Circuit To Ground
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Fig 21: Checking PCM Connector C-114 For Open Or Short Circuit To Ground
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Q: Are the harness wires in good condition?
1. YES: Go to Step 13.
2. NO: Repair or replace the harness wire.
STEP 13. Check the harness for an open or short circuit to ground between A/T control solenoid valve assembly connector B-15 (terminals 6, 7, and 10) and solenoid valve connectors B-15-4 and B-15-5.

Fig 22: Checking A/T Control Solenoid Valve Assembly Connector B-15 For Open Or Short Circuit To Ground
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Fig 23: Checking Solenoid Valve Connectors B-15-4 & B-15-5 For Open Or Short Circuit To Ground
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Q: Is the harness wire in good condition?
1. YES: Replace the PCM.
2. NO: Replace the harness wire.