Restraints and Safety Systems: Testing and Inspection
DIAGNOSTIC INSTRUCTIONS
The symptom chart can be used to help locate supplemental restraint system (SRS) concerns if no DTCs are retrieved and the listed symptoms are observed. Whether or not the listed symptoms are observed, always carry out the following:
1. Retrieve all DTCs stored in the RCM memory and occupant classification system module (OCSM) memory. Refer to Retrieve/Clear Continuous DTCs.
2. Run the On-Demand Self-Test to determine what DTCs are currently being sensed by the RCM and OCS module.
3. If on-demand DTCs are different than continuous memory DTCs, always repair the on-demand DTCs first.A DTC can indicate several concerns. The DTCs are to assist in system diagnosis and are not to be considered definitive. Always see the pinpoint test corresponding to the DTC to determine where the concern lies and to repair the concern correctly.
Diagnostic Test Options
Scan tool options:
- Retrieve/Clear Continuous Memory DTCs
- On-Demand Self-Test
Refer to the manufacturer's literature for the scan tool being used for correct scan tool test options.
Self-Test/On-Demand
The on-demand Self-Test option is used to verify that no electrical concerns exist with the air bag SRS. Upon entering the self-test, the restraints control module (RCM)/occupant classification system module (OCSM) will make an electrical check of each electrical component in the system. If a concern is detected, a DTC is displayed on the scan tool with a brief description of the DTC. The self-test should always be run after any repair to verify that the repair was successful.To run the on-demand Self-Test, follow these steps:
1. Connect the scan tool to the data link connector (DLC).
2. Turn the ignition switch to the ON position.
3. Follow the manufacturer's instructions for the scan tool being used.
4. Select RCM or OCSM.
5. Select Self-Test.
6. The module will run the self-test and display on-demand (reflecting hard system concerns) and continuous memory (historic) DTCs on the scan tool.
Self-Test/Continuous Memory and Clear DTCs
During vehicle operation, the RCM and OCSM will detect and store both intermittent and hard failure DTCs in non-volatile memory. The DTC strategy employed by the RCM incorporates a time-out scheme for determining when a concern exists in the system. This requires a concern to exist for up to one minute in the system before the RCM will detect it. For the RCM to determine that a concern no longer exists, the concern must be absent for up to one minute. The actual detection time-outs vary with each DTC. DTCs can be retrieved with a scan tool using the Self-Test option. All DTCs stored in the RCM and OCSM will be displayed on the scan tool along with a brief description of the DTC. If no DTCs are present, the scan tool will display a SYSTEM PASSED message. This option can also be used to clear DTCs from the RCM and OCSM memory, as long as the concern no longer exists.Once 75 hours of operation have been recorded by the RCM since the concern was last detected, all RCM continuous memory DTCs will automatically be removed from memory.
Once 128 key cycles have been recorded by the OCSM since the concern was last detected, all OCSM continuous memory DTCs will automatically be removed from memory.To retrieve or clear DTCs, follow these steps:
1. Connect the scan tool to the data link connector (DLC).
2. Turn the ignition switch to the ON position.
3. Follow the manufacturer's instructions for the scan tool being used.
4. Select RCM or OCSM.
5. Select Self-Test.
NOTE: Before proceeding with the clearing operation, make note of the DTCs displayed. Once cleared, DTCs cannot be retrieved.
6. All DTCs will be displayed on the screen.
7. Clear the DTCs. After clearing the DTCs, cycle the key OFF, then ON.
- Continuous memory DTCs that have been cleared will not reoccur as "continuous memory" in the same key cycle. Only new DTCs which were not present before clearing can occur as "continuous memory" after clearing.
DataLogger PID/Data
The DataLogger PID/Data option allows the scan tool operator to read the state of several parameter IDs (PIDs) to aid in diagnosing the system. PIDs are real time measurements of parameters, such as voltages and resistances, calculated by the restraints control module (RCM) sent to the scan tool for display. Many of the PIDs supported by the modules are calculated periodically and are, therefore, not true real time readings.To retrieve PIDs, follow these steps:
1. Connect the scan tool to the DLC.
2. Turn the ignition switch to the ON position.
3. Follow the manufacturer's instructions for the scan tool being used.
4. Select RCM or OCSM.
5. Select DataLogger.
Active Commands
Occupant Classification System Module (OCSM)
System Reset active command sets the zero set point or rezeros the occupant classification sensor (OCS) system. See - Occupant Classification Sensor - Original Equipment Removal/Installation or Procedures.
Instrument Cluster Module (IC)
These commands allow the technician to verify the operation of (IC) module components and subsystems.
Lamp Fault Codes
This vehicle supports lamp fault codes (LFC) only when the restraints control module (RCM) is in plant mode. A new RCM installed to a vehicle will be in plan mode until:
- programmable module installation (PMI) has been carried out.
- the RCM sees a fault-free SRS (no DTCs present).
If a LFC is present after completing PMI, a fault is present in the SRS and on-demand DTCs must be retrieved and diagnosed.
Diagnosing Customer Concerns With On-Demand DTCs
NOTE: Most SRS diagnostic procedures will require depowering and repowering of the SRS. Depowering and repowering requires disconnecting of the battery and removal of the restraints control module (RCM) fuse. This reduces the risk of accidental deployment of SRS components while diagnostic procedures are being carried out.
If the air bag warning indicator is reported ON by the customer when the vehicle comes in for service, connect the scan tool and follow the diagnostic instruction procedures to identify the concern.Once the DTC is known, read the Normal Operation of the pinpoint test for the DTC involved.Using the scan tool with the use of PIDs and active command(s) may be of assistance in diagnosing the concern.
- Follow the depowering procedure as directed.
- Determine the location of components involved in creating the DTC.
- Carry out a thorough visual inspection of:
- Components
- Connectors
- Splices and wiring harnesses
- Insulation on conductors
Diagnosing Customer Concerns With Continuous Memory DTCs
If an air bag warning indicator ON is reported by the customer but is not present when the vehicle comes in for service, follow the Diagnostic Instruction procedures to identify the intermittent DTC.Once the DTC is known, read the Normal Operation section of the pinpoint test for the DTC involved.
- Follow the depowering procedure as directed.
- Determine the location of components involved in creating the DTC.
- Carry out a thorough visual inspection of:
- Components
- Connectors
- Splices and wiring harnesses
- Insulation on conductors
Refer to the Possible Causes section of the pinpoint test for the DTC involved, which lists the common concerns that relate to the DTC. Concerns are listed according to priority.
Fault PIDs
There are 2 types of fault PIDs that can be reported by the restraints control module (RCM) and/or occupant classification system module (OCSM). The first type, considered conventional, has only one level of fault reporting and identifies a specific concern for a given component and points to a particular diagnostic path, example: DTC B1317 (Battery Voltage High).The second type uses a process within the software of the controller that maps the byte and bit to name a specific device and fault condition. This process is called Bit-mapping and referred to as fault PIDs in the diagnosis of the vehicle. This type does not identify the specific concern or component on the first level of fault reporting, Example: DTC B2293 (Restraint system - Airbag Fault). DTC B2293 can have up to 28 specific on-demand fault PIDs (areas of concern) associated with this DTC.Those associated fault PIDs are an extension of the information provided by the DTC and are identified by the same DTC number. A scan tool must be used to view DTCs and their fault PIDs. Once a scan tool has retrieved a DTC, use the scan tool to view the fault PIDs. In the diagnostic path, other types of PIDs are sometimes used to determine the root cause (example: resistance or voltage PIDs)When viewing of fault PIDs has been carried out, the scan tool can display the PIDs associated with that DTC, including the status or state that exists (on-demand [active] DTC) or existed (continuous memory [historic]) DTC. Refer to the manufacturer instructions for the scan tool being used on how to view fault PIDs.
Prove Out Procedure
Turn the ignition switch from the OFF to the ON position and visually monitor the air bag warning indicator with all supplemental restraint system (SRS) components connected. The air bag warning indicator will light continuously for approximately 6 seconds and then turn off. If an SRS fault is present, the air bag warning indicator will:
- fail to light.
- remain lit continuously.
- flash.The air bag warning indicator may not illuminate until approximately 30 seconds after the ignition switch has been turned from the OFF to the ON position. This is the time required for the restraints control module (RCM) to complete the testing of the SRS. If the air bag warning indicator is inoperative and an SRS fault exists, a chime will sound in a pattern of 5 sets of 5 beeps. If this occurs, the air bag warning indicator will need to be repaired before diagnosis can continue.
Air Bag Reconnect Checklist
The checklist below should be completed following diagnosis or repair of any air bag system concern:
- All in-seat harness connectors connected?
- Clockspring connectors connected?
- Occupant classification sensor (OCS) system connected?
- All air bag modules connected?
- All safety canopy modules connected?
- All safety belt pretensioner connectors connected?
- All safety belt retractor pretensioners connectors connected?
- Passenger air bag deactivation (PAD) indicator connected?
- Restraints control module (RCM) connected?
- All sensors (front and side impact, seat position and safety belt tension) connected?
- RCM fuse installed?
- Battery connected?
Air Bag Module Second Stage Deployment Check
Because the driver and passenger front air bags each have 2 deployment stages, it is possible that Stage 1 has deployed and Stage 2 has not.
If a front air bag module has deployed, it is mandatory that the front air bag module be remotely deployed using the appropriate air bag disposal procedure to make sure the second stage has been deployed.
- For information on driver air bag module and/or passenger air bag module remote deployment, see - Air Bag Disposal - Driver, Undeployed, Scrapped Vehicle or - Air Bag Disposal - Passenger, Undeployed, Scrapped Vehicle.
Glossary
Disconnect the Component
Disconnect the component means to disconnect the component vehicle harness connector, not to remove the component. Do not reconnect a disconnected component unless instructed to do so.
Deactivate the System
Deactivate the system means to carry out a deactivation procedure. See Supplemental Restraint System (SRS) Deactivation And Reactivation.
Depower the System
Depower the system means to disconnect the battery and remove the restraints control module (RCM) fuse. See Supplemental Restraint System (SRS) Depowering And Repowering.
Deployment Loop
The deployment loop is made up of the RCM, deployable device, air bag(s), safety belt pretensioners (safety canopies, deployable steering columns, load limiting retractor, adaptive tether, adaptive vent, if equipped) and associated circuits.
Install a New Component
Install a new component means to remove the existing component and install a new authorized part obtained from Mazda North American Operations.
Prove Out the Supplement Restraint System (SRS)
Prove out the system means to turn the ignition switch from the OFF to the ON position and visually monitor the air bag warning indicator with all SRS components connected. The air bag warning indicator will light continuously for approximately 6 seconds and then turn off. If an SRS fault is present, the air bag warning indicator will either fail to light or remain lit continuously. The air bag warning indicator may not illuminate until approximately 30 seconds after the ignition switch has been turned from the OFF to the ON position. This is the time required for the RCM to complete the testing of the SRS. If the air bag warning indicator is inoperative and an SRS fault exists, a chime will sound in a pattern of 5 sets of 5 beeps. If this occurs, the air bag warning indicator will need to be repaired before diagnosis can continue.
Reactivate the System
Reactivate the system means to carry out the reactivation procedure. See Supplemental Restraint System (SRS) Deactivation And Reactivation.
Reconnect the System
Reconnect the system means to reconnect all system components. See Air Bag System Reconnect Checklist.
Repower the System
Repower the system means, turn the ignition ON, install the RCM fuse and connect the battery ground cable. See Supplemental Restraint System (SRS) Depowering And Repowering.
Secondary Air Bag Warning
The secondary air bag warning is an audible fault format that consists of 5 sets of 5 tone bursts, with each set of 5 tone bursts separated by a 5-second quiet period. One tone burst cycle will consist of one-second ON and one-second OFF. This series of 5 activations is repeated every 30 minutes.
Squib
A squib (igniter) is a device designed to convert electrical energy to the heat energy necessary to deploy a pyrotechnic restraints system device.
Inspection and Verification
1. Verify the customer concern by checking the air bag warning indicator in the instrument cluster. Refer to Prove Out the System.
2. Visually inspect for obvious signs of mechanical or electrical damage. Do not disconnect electrical connectors until directed to do so within the pinpoint test.
3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
NOTE: Make sure to use the latest scan tool software release.
4. If the cause is not visually evident, connect the scan tool to the data link connector (DLC).
NOTE: The vehicle communication module (VCM) LED prove-out confirms power and ground from the data link connector (DLC) are provided to the VCM.
5. If the scan tool does not communicate with the VCM:
- check the VCM connection to the vehicle.
- check the scan tool connection to the VCM.
- See - Communications Network - Troubleshooting, No Power To The Scan Tool, to diagnose no communication with the scan tool.
6. If the scan tool does not communicate with the vehicle:
- verify the ignition key is in the ON position.
- verify the scan tool operation with a known good vehicle.
- See - Communications Network - Troubleshooting, to diagnose no response from the PCM.
7. Carry out the network test.
- If the scan tool responds with no communication for one or more modules, see - Communications Network - Troubleshooting.
- If the network test passes, retrieve and record on-demand and continuous memory DTCs from the RCM and occupant classification sensor (OCS) module.
8. If the DTCs retrieved are related to the concern, See the Supplemental Restraint System (SRS) DTC Chart. Diagnostic Instructions - DTC Chart For all other DTCs, see - Diagnostic Trouble Code (DTC) Chart - B, C, P And U Codes.
9. If no DTCs related to the concern are retrieved, GO to Symptom Related Diagnostic Procedures.