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Home >> Chrysler >> 2003 >> Sebring Coupe V6-3.0L VIN H >> Repair and Diagnosis >> Restraints and Safety Systems >> Air Bag Systems >> Testing and Inspection >> Symptom Related Diagnostic Procedures >> Diagnosis By Symptom >> Symptom Procedures

Symptom Procedures

Communication with Scan Tool MB991502 is not Possible. (Communication is not Possible with SRS.)

SRS-ECU Power Supply Circuit:




Connectors:








CIRCUIT OPERATION
- The SRS-ECU is powered from the ignition switch (IG1).
- The SRS-ECU power is supplied from two circuits. Even if one circuit is shut off, the air bag can inflate.
- The SRS system diagnosis can be done by connecting scan tool MB991502 to the data link connector.

TECHNICAL DESCRIPTION (COMMENT)
If communication is not possible with the SRS only, the cause is probably an open circuit in the on-board diagnostic output circuit of the SRS or in the power circuit (including ground circuit).

TROUBLESHOOTING HINTS
- Damaged wiring harnesses or connectors
- Malfunction of the SRS-ECU
- Incorrect scan tool (MUT-II) ROM pack

DIAGNOSIS

Required Special Tool:
- MB991223 (MB991222): Harness Set (Probe)

STEP 1. Check that the scan tool can communicate with the other systems.

Q: Can the scan tool communicate with the other systems?

YES: Go to Step 2.
NO: 2.4L: Refer to Symptom Procedures 3.0L: Refer to Symptom Procedures.

STEP 2. Check the communication line between the SRS-ECU and the scan tool.







1. Disconnect the SRS-ECU connector C-137 and the data link connector C-26, and measure at the wiring harness side.

CAUTION: Do not insert a test probe into the terminal of the SRS-ECU connector C-137 from its front side directly as the connector contact pressure may be weakened.




2. Check for continuity between the following terminals.
C-137 connector C-26 connector

16 - 7

It should be less than 2 ohms.

Q: Does continuity exist?

YES: Go to Step 3.
NO: Go to Step 5.

STEP 3. Check the ground circuit to the SRS-ECU.




1. Disconnect the SRS-ECU connector C-137, 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.




2. Check for continuity between terminal 3 and body ground. It should be less than 2 ohms.

Q: Does continuity exist?

YES: Go to Step 4.
NO: Go to Step 6.

STEP 4 Check the power supply circuit to the SRS-ECU.




1. Disconnect the SRS-ECU connector C-137, and measure at the wiring harness side.
2. Connect the negative battery terminal.
3. Turn the ignition switch to the "ON" position.

CAUTION: Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.




4. Measure the voltage between terminals 9,12 and body ground.
Voltage should be 9 volts or more.

Q: Is the measured voltage within the specified range?

YES: Recheck the trouble symptom. If it is not solved, replace the SRS-ECU. Then go to Step 8.
NO: Go to Step 7.










STEP 5. Check the harness wires between the SRS-ECU connector C-137 (terminal No.16) and the data link connector C-26 (terminal No.7).

NOTE: After inspecting the intermediate connector C-140, inspect the wiring harness. If the intermediate connector C-140 is damaged, repair or replace it. Refer to Harness Connector Inspection. Then go to Step 8.

Q: Is the harness wire between the SRS-ECU connector C-137 (terminal No.16) and the data link connector C-26 (terminal No.7) in good condition?

YES: Go to step 8.
NO: Repair the harness wire between the SRS-ECU connector C-137 and the data link connector C-26. Then go to Step 8.







STEP 6. Check the harness wire between the SRS-ECU connector C-137 (terminal No.3) and ground.

Q: Is the harness wire between the SRS-ECU connector C-137 (terminal No.3) and ground in good condition?

YES: Go to Step 8.
NO: Repair the harness wire between the SRS-ECU connector C-137 and ground. Then go to Step 8.




STEP 7. Check the harness wires between the SRS-ECU connector C-137 (terminal No.9 and 12) and the ignition switch connector C-202 (terminal No.2).

NOTE: After inspecting the intermediate connectors C-308 and C-311, inspect the wiring harnesses. If the intermediate connector C-308 or C-311 is damaged, repair or replace it. Refer to Harness Connector Inspection. Then go to step 8.







Q: Are the harness wires between the SRS-ECU connector C-137 (terminal No.9 and 12) and the ignition switch connector C-202 (terminal No.2) in good condition?

YES: Go to Step 8.
NO: Repair the harness wires between the SRS-ECU connector C-137 and the ignition switch connector C-202. Then go to Step 8.

STEP 8. Retest the system.

Q: Does the scan tool communicate normally with the SRS system?

YES: The procedure is complete. (If no malfunctions are not found in all steps, an intermittent malfunction is suspected. Refer to INTRODUCTION, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction.)
NO: There is no action to be taken.

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