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Home >> Mitsubishi >> 2002 >> Lancer O-Z Rally Edition L4-2.0L SOHC >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> Manufacturer Code Charts >> Air Bag Systems >> DTC 28

DTC 28

Passenger's (Front) Seat Belt Pre-Tensioner (Squib) System Fault 1 (Short Circuit between Terminals of the Squib Circuit)

Passenger's (Front) Seat Belt Pre-tensioner (Squib):




Connector:






CIRCUIT OPERATION
- If an analog G-sensor and safing G-sensor inside the SRS-ECU sense a predetermined collision energy simultaneously during a frontal collision, the SRS-ECU sends igniting signal to the pre-tensioner, causing the pre-tensioner to operate.

DTC SET CONDITIONS
- These DTC are output if there is abnormal resistance between the input terminals of the passenger's seat belt pre-tensioner (squib).

TROUBLESHOOTING HINTS
- Improper engaged connector or defective short bar*
- Short circuit between the passengers seat belt pre-tensioner (squib) circuit terminals
- Damaged connectors
- Malfunction of the SRS-ECU

NOTE: *: The squib circuit connectors integrate a "short" bar (which prevents the air bag from deploying unintentionally due to static electricity by shorting the positive wire to the ground wire in the squib circuit when the connectors are disconnected) Therefore, if connector C-13 or D-03 is damaged or improperly engaged, the short bar may not be released when the connector is connected.

DIAGNOSIS

Required Special Tools:
- MB991502: Scan Tool (MUT-II)
- MB991865: Dummy resister
- MB991866: Resister harness

STEP 1. Check the DTC.

Q: Is DTC 34 output?

YES: Go to Step 2.
NO: Go to Step 3.




STEP 2. Check the SRS-ECU connector C-13.

Q: Is connector correctly engaged?

YES: Go to Step 3.
NO: Engage the connector correctly. Then go to Step 7.




Connector:




STEP 3. Check SRS-ECU connector C-13 and passenger's seat belt pre-tensioner connector D-03.
1. Disconnect connectors C-13 and D-03, and then reconnect them.
2. Connector the negative battery terminal.
3. Erase the DTC memory, and then recheck the DTC.

Q: Is DTC 28 output?

YES: Go to step 4.
NO: The inspection is complete. It is assumed that DTC 28 set as connector C-13 or D-03 was engaged improperly.




STEP 4. Check the passenger's seat belt pre-tensioner.
1. 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.

2. Disconnect the passenger's seat belt pre-tensioner connector D-03, and insert special tool MB991866 into the harness side connector by backprobing.
3. Connect the negative battery terminal.
4. Erase DTC memory, and then recheck the DTC.

Q: Is DTC 28 output?

YES: Go to Step 5.
NO: Replace the passenger's seat belt pre-tensioner. Then go to step 7.

STEP 5. Check the harness for short circuit between SRS-ECU and the passenger's seat belt pre-tensioner.




1. Disconnect SRS-ECU connector C-13.

Connector:






CAUTION: To release the short bar in the SRS-ECU connector, disconnect connector D-03 to short the squib circuit.

2. Disconnect passenger's seat belt pre-tensioner connector D-03.






CAUTION: Insert an insulator such as a cable tie to a depth of 4 mm (0.16 inch) or more, otherwise the short bar will not be released.

3. Insert a cable tie [3 mm (0.12 inch) wide, 0.5 mm (0.02 inch) thick] between terminals 29, 30 and the short bar to release the short bar.
4. 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.




5. Check the continuity between terminals 29 and 30. There should be open circuit.

Q: Is the continuity normal?

YES: Erase the DTC memory, and recheck if any DTC sets. If DTC 28 sets, replace the SRS-ECU. Then go to Step 7.
NO: Go to Step 6.




Connector:







STEP 6. Check the harness for short circuit between SRS-ECU connector C-13 and passenger's seat belt pre-tensioner connector D-03.

NOTE: After inspecting intermediate connector C-112, inspect the wiring harness.

If the intermediate connector C-112 is damaged, repair or replace it. Refer to Harness Connector Inspection.

Go to Step 7.

Q: Are harness wires between SRS-ECU connector C-13 connector and passenger's seat belt pre-tensioner connector D-03 in good condition?

YES: Go to step 7.
NO: Repair the harness wires between SRS-ECU connector C-13 and passenger's seat belt pre-tensioner connector D-03. Then go to step 7.

STEP 7. Check for DTC.

Q: Is DTC 28 output?

YES: Return to step 1.
NO: 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.)
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