Pinpoint Test C: The Restraints Control Module (RCM) Does Not Respond To The Scan Tool
Communications Network
Pinpoint Tests
Pinpoint Test C: The Restraints Control Module (RCM) Does Not Respond To The Scan Tool
Refer to Wiring Diagram Set 14, Module Communications Network for schematic and connector information. Diagrams By Number
Refer to Wiring Diagram Set 46, Supplemental Restraint System for schematic and connector information. Diagrams By Number
Normal Operation
The Restraints Control Module (RCM) communicates with the scan tool through the High Speed Controller Area Network (HS-CAN).
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Case ground open
- RCM
PINPOINT TEST C: THE RCM DOES NOT RESPOND TO THE SCAN TOOL
WARNING: Remove restraint system diagnostic tools from the vehicle prior to road testing. If tools are not removed, the supplemental restraint system (SRS) device may not deploy in a crash. Failure to follow this instruction may result in serious personal injury or death in a crash and possibly violate vehicle safety standards.
WARNING: Never probe the electrical connectors on air bag, Safety Canopy(R) or side air curtain modules. Failure to follow this instruction may result in the accidental deployment of these modules, which increases the risk of serious personal injury or death.
WARNING: Never disassemble or tamper with safety belt buckle/retractor pretensioners or adaptive load limiting retractors or probe the electrical connectors. Failure to follow this instruction may result in the accidental deployment of the safety belt pretensioners or adaptive load limiting retractors which increases the risk of serious personal injury or death.
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery.
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C1 CHECK THE RCM PINS FOR DAMAGE
- Ignition OFF.
- Depower the Supplemental Restraint System (SRS). Refer to Restraint Systems.
- Disconnect: RCM C2041a and C2041b.
- Inspect the RCM C2041a, harness side and the RCM C2041a, component side, pins 17 and 18 for damage.
- Are the RCM connector pins 17 and 18 OK?
Yes
GO to C2.
No
REPAIR the RCM connector pins as necessary. REPOWER the SRS. REFER to Restraint Systems. CLEAR the DTCs. REPEAT the network test with the scan tool.
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C2 CHECK THE RCM VOLTAGE SUPPLY CIRCUIT FOR AN OPEN
- Deactivate the SRS. Refer to Restraint Systems.
- Repower the SRS. Refer to Restraint Systems.
- Ignition ON.
- Measure the voltage between the RCM C2041b-13, circuit CBP08 (GY/YE), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to C3.
No
VERIFY the Smart Junction Box (SJB) fuse 8 (10A) is OK.
If OK, REPAIR the circuit.
If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. REACTIVATE the SRS. REFER to Restraint Systems. CLEAR the DTCs. REPEAT the network test with the scan tool. Diagrams By Number
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C3 CHECK THE RCM CASE GROUND
- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Measure the resistance between the RCM case and a good sheet metal ground near the RCM.
- Is the resistance less than 25 ohms?
Yes
GO to C4.
No
REPAIR the RCM case ground as necessary. CONNECT the negative battery cable. REACTIVATE the SRS. REFER to Restraint Systems. CLEAR the DTCs. REPEAT the network test with the scan tool.
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C4 CHECK THE HS-CAN CIRCUITS BETWEEN THE RCM AND THE DLC FOR AN OPEN
- Measure the resistance between the RCM C2041a-10, circuit VDB04 (WH/BU), harness side and the Data Link Connector (DLC) C251-6, circuit VDB04 (WH/BU), harness side.
- Measure the resistance between the RCM C2041a-9, circuit VDB05 (WH), harness side and the DLC C251-14, circuit VDB05 (WH), harness side.
- Are the resistances less than 5 ohms?
Yes
CONNECT the negative battery cable. GO to C5.
No
REPAIR the circuit in question. CONNECT the negative battery cable. REACTIVATE the SRS. REFER to Restraint Systems. CLEAR the DTCs. REPEAT the network test with the scan tool.
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C5 CHECK FOR CORRECT RCM OPERATION
- Disconnect all the RCM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the RCM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new RCM. REACTIVATE the SRS. REFER to Restraint Systems. CLEAR the DTCs. REPEAT the network test with the scan tool.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. REACTIVATE the SRS. REFER to Restraint Systems. CLEAR the DTCs. REPEAT the network test with the scan tool.
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