SRS Troubleshooting Process (AJA47433)

SRS TROUBLESHOOTING PROCESS

TECHNICAL SERVICE BULLETIN

SERVICE INFORMATION

SRS TROUBLESHOOTING TIPS

• Before doing any troubleshooting procedure, make sure the vehicle's battery is fully charged. If the battery charge is low, the SRS indicator may stay on.
• System voltage above 15.2 V can cause the SRS indicator to stay on. The indicator will usually be on only when a high voltage condition exists and may not set any DTCs. Correct any battery and charging system problems before troubleshooting the SRS system.
• Make sure the HDS communicates with the vehicle and the SRS unit. If it does not communicate, turn the ignition switch to LOCK (0) for 5 seconds, then turn it to ON (II) and make a second attempt. If the SRS unit still does not communicate with the HDS, do the "SRS Indicator Stays On, But No DTCs Are Stored, or Cannot Be Read" procedure, found under Symptom Troubleshooting in the SRS section in the vehicle service manual.
• On vehicles with reprogrammable SRS units, before replacing the SRS unit, check its software version with the HDS. If the software version is not the latest, update the SRS unit's software.
• Collision damage or improper collision repairs may set SRS DTCs. Always check for signs of collision damage, and verify that all the correct SRS parts were installed on the vehicle, as specified in the "Component Replacement/Inspection After Deployment" procedure, found in the SRS section of the vehicle service manual.
  NOTE: To determine what SRS parts were replaced, you may have to contact the body shop that did the collision work.
• Each SRS component is labeled with a part number. Always compare the factory original part numbers with those on the replacement parts. They should match, unless the part has been superseded. If a part number mismatch exists, determine the cause and the correct replacement part before further troubleshooting.
• While some SRS parts may appear to be interchangeable, always order replacement parts using the vehicle's VIN to ensure that you receive the correct SRS parts. Incorrect parts, or incorrectly installed SRS components, will set DTCs.
• The occupant detection system (ODS) or occupant position detection system (OPDS) may not initialize if there are SRS DTCs or an SRS unit problem. If normal troubleshooting doesn't resolve the problem, do this:
  • Loosen the seat mounting, shake the seat vigorously, then retorque the seat mounting bolts to the proper specification. This may free up a binding seat weight sensor so that initialization can occur.
  • To isolate whether the problem preventing initialization is in the seat or elsewhere in the system, install a known-good seat. If the SRS system initializes, the problem is in the original seat assembly. If it still won't initialize, the problem is in the SRS control unit, or another part of the SRS system.
  • Due to seat movement and wear, damaged seat wiring harnesses may cause DTCs and SRS/ODS initialization failures.
• If you have multiple SRS DTCs, troubleshoot them in the following order:
  1. SRS component deployment DTCs.
  2. DTCs related to power or ground connections.
  3. ECU internal failure DTCs.
  4. Any other DTCs beginning with the lowest number.