Diagnostic Trouble Code Procedures: Diagnosis
Required Special Tools:
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicle Communication Interface
- MB991827: MUT-III USB Cable
- MB991911: MUT-III Main Harness B
- MB991865: Dummy resister
- MB991866: Resister harness
- STEP 1. Using scan tool MB991958, read the diagnostic trouble code.
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Q: Is DTC 34 set?
- YES: Go to Step 2.
- NO: Go to Step 3.
- STEP 2. Check SRS-ECU connector C-72.
Q: Is the connector correctly engaged?
- YES: Go to Step 3.
- NO: Engage the connector correctly. Then go to Step 7.
- STEP 3. Check SRS-ECU connector C-72 and passenger's connector C-11.
- Disconnect the negative battery terminal.
- Disconnection connectors C-72 and C-11, and then reconnect them.
- Connect the negative battery terminal.
- Erase the DTC memory, and then check the DTC.
Q: Is DTC 24 set?
- YES: Go to Step 4.
- NO: The procedure is complete (It is assumed that DTC 24 set as connector C-72 or C-11 was engaged improperly).
- STEP 4. Check the passenger's air bag module (Using scan tool MB991958, read the diagnostic trouble code).
- Disconnect the negative battery terminal.
- Unclip passenger's air bag module connector C-11.
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- Connect special tool MB991865 to special tool MB991866.CAUTION: Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.
- Disconnect the passenger's air bag module connector C-11, and insert special tool MB991866 into the harness side connector by backprobing.
- Connect the negative battery terminal.
- Erase the DTC memory, and then recheck the DTC.
Q: Is DTC 24 output?
- YES: Go to Step 5.
- NO: Replace the passenger's air bag module. Refer to INSPECTION . Then go to Step 7.
- STEP 5. Check the harness for short circuit between SRS-ECU and the passenger's air bag module.
- Disconnect SRS-ECU connector C-72.
- Unclip passenger's air bag module connector C-11.CAUTION: To release the short spring in the SRS-ECU connector, disconnect connector C-11 to short the squib circuit.
- Disconnect the passenger's air bag module connector C-11.CAUTION: Insert an insulator such as a cable tie to a depth of 4mm (0.16 inch) or more, otherwise the short spring will not cable tie release.
- Insert a cable tie [3 mm (0.12 inch) wide, 0.5 mm (0.02 inch) thick] between terminals 5, 6 and the short spring to release the short spring.
- Measure at the wiring harness side.CAUTION: Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.
- Check for continuity between terminals 5 and 6.
- There should be open circuit.
Q: Does continuity exist?
- YES: Go to Step 6.
- NO: Eras the DTC memory, and recheck if any DTC sets. If DTC 24 sets, replace the SRS-ECU. Refer to HARNESS CONNECTOR . Then go to Step 7.
- STEP 6. Check the harness for short circuit between SRS-ECU connector C-72 (terminal No. 5 and 6) and passenger's side air bag module connector C-11 (terminal No. 1 and 2).
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Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Q: Are harness wires between SRS-ECU connector C-72 (terminal No. 5 and 6) and passenger's side air bag module connector C-11 (terminal No. 1 and 2) in good condition?
- YES: Go to Step 7.
- NO: Repair the harness wires between SRS-ECU connector C-72 and passenger's side air bag module connector C-11. Then go to Step 7.
- STEP 7. Recheck for diagnostic trouble code.
Q: Is DTC 24 output?
- YES: Return to Step 1.
- NO: The procedure is complete (If no malfunctions are found in all steps, an intermittent malfunction is suspected. Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).
Required Special Tools:
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicle Communication Interface
- MB991827: MUT-III USB Cable
- MB991911: MUT-III Main Harness B
- MB991223 (MB991222): Harness set (Probe)
- STEP 1. Check junction block multi-purpose fuse number 23.
Q: Is the fuse burned out?
- YES: Go to Step 4.
- NO: Go to Step 2.
- STEP 2. Check the circuit between the SRS-ECU and the ignition switch (IG1).
- Disconnect the negative battery terminal.
- Disconnect SRS-ECU connector C-72.
- Connect the negative battery terminal.
- Turn the ignition switch to the "ON" position.
- Measure at the wiring harness side.CAUTION: Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.
- Measure the Voltage between terminal 12 and body ground
- Voltage should measure 9 volts or more
Q: Is the measured voltage within the specified range?
- YES: Erase the DTC memory, and recheck if any DTC sets. If DTC 41 sets, replace the SRS-ECU. Refer to HARNESS CONNECTOR . Then go to Step 10.
- NO: Go to Step 3.
- STEP 3. Check the harness for open circuit between SRS-ECU connector C-72 (terminal No.9) and the ignition switch (IG1). NOTE: After inspecting intermediate connectors C-108 and C-111, inspect the wiring harness. If intermediate connectors are damaged, repair or replace them. Refer to HARNESS CONNECTOR INSPECTION . Then go to Step 10.
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Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Q: Are harness between SRS-ECU connector C-72 (terminal No.9) and the ignition switch (IG1) in good condition?
- STEP 4. Check a burned-out fuse.
- Replace the fuse.
- Turn the ignition switch to the "ON" position, wait for at least one minute and then turn the switch off.
- Check the fuse.
Q: Is the fuse in good condition?
- YES: Then go to Step 10.
- NO: Go to Step 5.
- STEP 5. Check the harness for short circuit to ground between the SRS-ECU and the junction block.
- Disconnect junction block connector C-108, and measure at the wiring harness side.CAUTION: Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.
- Check for continuity between terminal 24 and body ground.
- There should be open circuit.
Q: Does continuity exist?
- YES: Go to Step 8.
- NO: Go to Step 6.
- Disconnect junction block connector C-108, and measure at the wiring harness side.
- STEP 6. Check the harness for short circuit to ground between the junction block and the combination meter.
- Disconnect junction block connector C-108, and measure at the wiring harness side.CAUTION: Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.
- Check for continuity between terminal 25 and body ground.
- There should be open circuit.
Q: Does continuity exist?
- YES: Go to Step 7.
- NO: Check the other circuit, which flows through multi-purpose fuse number 23.
- Disconnect junction block connector C-108, and measure at the wiring harness side.
- STEP 7. Check the harness for short circuit to ground between junction block connector C-108 (terminal No.25) and combination meter connector C-41 (terminal No.52) Fig 9: Checking Harness For Short Circuit To Ground Between Junction Block Connector C-108 (Terminal No.25)
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Fig 10: Checking Harness For Short Circuit To Ground Between Combination Meter Connector C-41 Terminal No.52)Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
NOTE: After inspecting intermediate connectors C-42, inspect the wiring harness. If intermediate connectors are damaged, repair or replace them. Refer to HARNESS CONNECTOR INSPECTION . Then go to Step 10.Q: Are harness wires between junction block connector C-108 (terminal No.25) and combination meter connector C-41 (terminal No.52) in good condition?
- STEP 8. Check the harness for short circuit to ground between the SRS-ECU and the junction block.
- Disconnect SRS-ECU connector C-72, and measure at the wiring harness side.CAUTION: Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.
- Check for continuity between terminal 12 and body ground.
- There should be open circuit.
Q: Is the circuit normal?
- YES: Erase the DTC memory, and recheck if any DTC sets. If DTC 41 sets, replace the SRS-ECU. Refer to HARNESS CONNECTOR . Then go to Step 10.
- NO: Go to Step 9.
- Disconnect SRS-ECU connector C-72, and measure at the wiring harness side.
- STEP 9. Check the harness for short circuit ground between SRS-ECU connector C-72 (terminal No.24) and junction block connector C-108 (terminal No.12).
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Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Q: Are harness wires between SRS-ECU connector C-72 (terminal No.24) and junction block connector C-108 (terminal No.12) in good condition?
- YES: Go to Step 10.
- NO: Repair the harness wires between SRS-ECU connector C-72 and junction block connector C-108. Then go to Step 10.
- STEP 10. Recheck for diagnostic trouble code.
Q: Is DTC 41 output?
- YES: Return to Step 1.
- NO: The procedure is complete (If no malfunctions are found in all steps, an intermittent malfunction is suspected. Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).
Required Special Tools:
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicle Communication Interface
- MB991827: MUT-III USB Cable
- MB991911: MUT-III Main Harness B
- STEP 1. Check the SRS warning light.
- Disconnected the SRS-ECU connector C-72.
- Connect the negative battery terminal.
- Turn the ignition switch to the "ON" position.
Q: Does the warning light illuminate?
- YES: Erase the DTC memory, and recheck if any DTC sets. If DTC 43 sets, replace the SRS-ECU. Refer to HARNESS CONNECTOR . Then go to Step 6.
- NO: Go to Step 2.
- STEP 2. Check the ground line at the SRS-ECU connector C-72.
- Disconnect SRS-ECU connector C-72.
- Connect the negative battery terminal.CAUTION: Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.
- Measure the continuity between terminal 3 and ground.
- Should be less than 2 ohms.
Q: Does continuity exist?
- YES: Go to Step 3.
- NO: Go to Step 5.
- STEP 3. Check the SRS warning light bulb.
Q: Has the SRS warning light bulb blown?
- YES: Replace the SRS warning light bulb. Then go to Step 6.
- NO: Go to Step 4.
- STEP 4. Check the harness for open circuit between SRS-ECU connector C-72 (terminal No.4) and the ignition switch (IG1).
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NOTE: After inspecting combination meter connectors C-41, C-42 and junction block connectors C-108, C-111, inspect the wiring harness. If intermediate connectors C-41, C-42, C-108, C-111 are damaged, repair or replace them. Refer to HARNESS CONNECTOR INSPECTION . Then go to Step 5.Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Q: Are the harness wires between SRS-ECU connector C-72 (terminal No.4) and the ignition switch (IG1) in good condition?
- YES: Replace the combination meter.
- NO: Repair the harness wires between SRS-ECU connector E-08 and the ignition switch (IG1). Then go to Step 6.
- STEP 5. Check the harness for open circuit between SRS-ECU connector C-72 (terminal No.3) and ground.
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Q: Is the harness wire between SRS-ECU connector C-72 (terminal No.3) and ground in good condition?
- YES: Go to Step 6.
- NO: Repair the harness wires between SRS-ECU connector C-72 and ground. Then go to Step 6.
- STEP 6. Recheck for diagnostic trouble code.
Q: Is DTC 43 output?
- YES: There is no action to be taken.
- NO: The procedure is complete (If no malfunctions are found in all steps, an intermittent malfunction is suspected. Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).
Required Special Tools:
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicle Communication Interface
- MB991827: MUT-III USB Cable
- MB991911: MUT-III Main Harness B
- MB991865: Dummy resister
- MB991866: Resister harness
- STEP 1. Using scan tool MB991958, read the diagnostic trouble code.
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Q: Is DTC 34 set?
- YES: Go to Step 2.
- NO: Go to Step 3.
- STEP 2. Check SRS-ECU connector C-74.
Q: Is the connector correctly engaged?
- YES: Go to Step 3.
- NO: Engage the connector correctly. Then go to Step 7.
- STEP 3. Check SRS-ECU connector C-74 and side-air bag module (RH) connector D-19 (Using scan tool MB991958, read the diagnostic trouble code).
- Disconnect the negative battery terminal.
- Disconnection connectors C-74 and D-19, and then reconnect them.
- Connect the negative battery terminal.
- Erase the DTC memory, and then recheck the DTC.
Q: Is DTC 71 output?
- YES: Go to Step 4.
- NO: The procedure is complete (It is assumed that DTC 71 set as connector C-74 or D-19 was engaged improperly).
- STEP 4. Check the side-airbag module (Using scan tool MB991958, read the diagnostic trouble code).
- Disconnect the negative battery terminal.
- Connect special tool MB991865 to special tool MB991866.CAUTION: Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.
- Disconnect the side-airbag module (RH) connector D-19, and insert special tool MB991866 into the harness side connector by backprobing.
- Connect the negative battery terminal.
- Erase the DTC memory, and then recheck the DTC.
Q: Is DTC 71 set?
- YES: Go to Step 5.
- NO: Replace the seat back assembly of the front seat (RH). Refer to DISASSEMBLY AND ASSEMBLY . Then go to Step 7.
- STEP 5. Check the harness for short circuit between SRS-ECU and the side-airbag module (RH).
- Disconnect SRS-ECU connector C-74.
CAUTION: To release the short spring in the SRS-ECU connector, disconnect connector D-19 to short the squib circuit.
- Disconnect side-airbag module connector D-19.
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CAUTION: Insert an insulator such as a cable tie to a depth of 4mm (0.16 inch) or more, otherwise the short spring will not cable tie release. - Insert a cable tie [3 mm (0.12 inch) wide, 0.5 mm (0.02 inch) thick] between terminals 23, 24 and the short spring to release the short spring.
- Measure at the wiring harness side.CAUTION: Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.
- Check for continuity between terminals 23 and 24.
- There should be open circuit.
Q: Does continuity exist?
- YES: Go to Step 6.
- NO: Erase the DTC memory, and recheck if any DTC sets. If DTC 71 sets, replace the SRS-ECU. Refer to HARNESS CONNECTOR . Then go to Step 7.
- Disconnect SRS-ECU connector C-74.
- STEP 6. Check the harness wires for short circuit between SRS-ECU connector C-74 (terminal No.23 and 24) and side-airbag module (RH) connector D-19 (terminal No.1 and 2)
Q: Are the harness wires between SRS-ECU connector C-74 (terminal No.23 and 24) and side-airbag module (RH) connector D-19 (terminal No.1 and 2) in good condition?
- YES: Go to Step 7.
- NO: Repair the harness wires between SRS-ECU connector C-74 and side-airbag module connector D-19. Then go to Step 7.
- STEP 7. Recheck for diagnostic trouble code.
Q: Is DTC 71 set?
- YES: Return to Step 1.
- NO: The procedure is complete (If no malfunctions are found in all steps, an intermittent malfunction is suspected. Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).
Required Special Tools:
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicle Communication Interface
- MB991827: MUT-III USB Cable
- MB991911: MUT-III Main Harness B
- MB991865: Dummy resister
- MB991866: Resister harness
- STEP 1. Check the side-airbag module (RH) (Using scan tool MB991958, read the diagnostic trouble code).
- Disconnect the negative battery terminal.
- Connect special tool MB991865 to special tool MB991866.CAUTION: Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.
- Disconnect the side-airbag module (RH) connector D-19, and insert special tool MB991866 into the harness side connector by backprobing.
- Connect the negative battery terminal.
- Erase the DTC memory, and then recheck the DTC.
Q: Is the circuit normal?
- YES: Go to Step 2.
- NO: Replace the seat back assembly of the front seat (RH). Refer to DISASSEMBLY AND ASSEMBLY . Then go to Step 4.
- STEP 2. Check the harness for short circuit to power supply between SRS-ECU and the side-airbag module (RH).
- Disconnect SRS-ECU connector C-74.
- Disconnect side-airbag module (RH) connector D-19.
- Turn the ignition switch to the "ON" position.
- Measure at the wiring harness side.CAUTION: Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.
- Measure the voltage between terminals 23, 24 and body ground.
- Voltage should measure 0 volt.
Q: Is the measured voltage within the specified range?
- YES: Erase the DTC memory, and recheck if any DTC sets. If DTC 75 sets, replace the SRS-ECU. Refer to HARNESS CONNECTOR . Then go to Step 4.
- NO: Go to Step 3.
- STEP 3. Check the harness wires for short circuit to power supply between SRS-ECU connector C-74 (terminal No.23 and 24) and side-airbag module (RH) connector D-19 (terminal No.1 and 2).
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Q: Are the harness wires between SRS-ECU connector C-74 (terminal No.23 and 24) and side-airbag module (RH) connector D-19 (terminal No.1 and 2) in good condition?
- YES: Go to Step 4.
- NO: Repair the harness wires between SRS-ECU connector C-74 and side-airbag module (RH) connector D-19. Then go to Step 4.
- STEP 4. Recheck for diagnostic trouble code.
Q: Is DTC 75 output?
- YES: Return to Step 1.
- NO: The procedure is complete (If no malfunctions are found in all steps, an intermittent malfunction is suspected. Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).