DTC B0070 or B0072

Diagnostic Instructions Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Review Strategy Based Diagnosis for an overview of the diagnostic approach. Diagnostic Procedure Instructions provides an overview of each diagnostic category. DTC Descriptors DTC B0070 Driver Seat Belt Anchor Plate Tensioner DTC B0072 Co-Driver Seat Belt Anchor Plate Tensioner For symptom byte information refer to Symptom Byte List. Diagnostic Fault Information

Circuit	Circuit Functio	Short to n Ground	Low Resista	High ncReesista	Open ncCeircuit	Short to Voltage	Signal Performa
3481	Control	B0070 11	B0070 1A	B0070 1B	B0070 13	B0070 12	—
3482	Control	B0070 11	B0070 1A	B0070 1B	B0070 13	B0070 12	—
3479	Control	B0072 11	B0072 1A	B0072 1B	B0072 13	B0072 12	—
3480	Control	B0072 11	B0072 1A	B0072 1B	B0072 13	B0072 12	—

Circuit/System Description For an overview of the component/system, refer to: Supplemental Inflatable Restraint System Description and Operation The F113D Seat Belt Anchor Plate Tensioner — Driver and F113P Seat Belt Anchor Plate Tensioner — Passenger are pyrotechnic units that contain an ignitor, which, when supplied with voltage, ignites the propellant in the gas generator. The F113 Seat Belt Anchor Plate Tensioners are respectively located on the driver and passenger center pillars. The deployment loop has a high control circuit that will supply voltage to deploy the pretensioner and a low control that will supply ground to deploy the pretensioner. The F113D Seat Belt Anchor Plate Tensioner — Driver uses circuit 3481 as high control and circuit 3482 as low control. The F113P Seat Belt Anchor Plate Tensioner — Passenger uses circuit 3479 as high control and circuit 3480 as low control. Based on inputs from the impact sensors, the K36 Restraints Control Module will command deployment of the F113 Seat Belt Anchor Plate Tensioners by simultaneously applying voltage to the high control circuit, and ground to the low control circuit Conditions for Running the DTC Ignition voltage is between 9–16 V. Ignition ON Conditions for Setting the DTC B0070 11 Circuit 3481 or circuit 3482 is shorted to ground for 2 s B0072 11 Circuit 3479 or circuit 3480 is shorted to ground for 2 s B0070 12 Circuit 3481 or circuit 3482 is shorted to voltage for 2 s B0072 12 Circuit 3479 or circuit 3480 is shorted to voltage for 2 s B0070 13 Circuit 3481 or circuit 3482 is open for 2 s B0072 13 Circuit 3479 or circuit 3480 is open for 2 s B0070 1B Circuit 3481 or circuit 3482 resistance is greater than 4.2 Ω for 2 s B0072 1B Circuit 3479 or circuit 3480 resistance is greater than 4.2 Ω for 2 s B0070 1A Circuit 3481 or circuit 3482 resistance is less than 1.4 Ω for 2 s B0072 1A Circuit 3479 or circuit 3480 resistance is less than 1.4 Ω for 2 s Action Taken When the DTC Sets Airbag Indicator ON. The inflatable restraint sensing and diagnostic module will store a DTC, however if an event occurs the system will still attempt deployment. Conditions for Clearing the DTC The current DTC will clear when the diagnostic runs and passes. A history DTC will clear after 100 consecutive malfunction-free ignition cycles.. Diagnostic Aid

Note

The following diagnostic aids apply for both current and history DTCs. Refer to SIR Disabling and Enabling. Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with a reappearance of the malfunction. If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections. An incorrectly seated connector can cause an open/high resistance condition. Check the circuit terminals for fretting or incorrectly seated connector if a DTC with symptom byte 1B is set. Reference Information Schematic Reference SIR Schematics Connector End View Reference Master Electrical Component List Description and Operation Supplemental Inflatable Restraint System Description and Operation Electrical Information Reference Circuit Testing Testing for Intermittent Conditions and Poor Connections Wiring Repairs Connector Repairs Scan Tool Reference Control Module References for scan tool information Special Tools EL-38125-580 Terminal Release Tool Kit Circuit/System Verification

Note

The condition may be intermittent and require driving the vehicle, then reviewing the snapshot to verify resistance parameters do not drop out or spike. Refer to Testing for Intermittent Conditions and Poor Connections

1. Verify the appropriate scan tool Deployment Loop Resistance parameters stay consistently between 2.1 and 4.0 Ω for the F113 Seat Belt Anchor Plate Tensioner. ⇒ If less than 2.1 Ω or greater than 4.0 Ω Refer to Circuit/System Testing. ⇓ If between 2.1–4.0 Ω without any spikes or dropouts
2. A fault is not currently present and may be an intermittent condition. Circuit/System Testing

Note

Refer to SIR Service Precautions. Refer to SIR Disabling and Enabling. Always test the harness side when circuit testing deployment loops. Never test a component on a deployment loop with the DVOM. Inspect all terminals for damage or corrosion when disconnecting connectors. Damage or corrosion in the following requires repair or replacement of the affected component/connector. – Seat Belt Anchor Plate Tensioner – Restraints Control Module – Seat Belt Anchor Plate Tensioner wiring harness connector – Restraints Control module wiring harness connector The connector and connector position assurance (CPA) may seat independent of each other. Both the connector and CPA should seat with an audible and/or tactile click.

1. Ignition OFF.
2. Verify the SIR system is disabled.
3. Disconnect the harness connector at the appropriate F113 Seat Belt Anchor Plate Tensioner.
4. Test for greater than 25 Ω between the control circuit terminals 1 and circuit terminal 2. ⇒ If 25 Ω or less 4.1. Disconnect the X2 harness connector at the K36 Restraints Control Module. 4.2. Verify the appropriate circuits are not shorted together: DTC B0070 = Circuit 3481 and circuit 3482 DTC B0072 = Circuit 3479 and circuit 3480 ⇒ If a short between the circuit is found, repair the fault on the circuit. ⇓ If a short between the circuits is not found 4.3. Replace the K36 Restraints Control Module. ⇓ If greater than 25 Ω
5. Ignition ON.
6. Verify the SIR system is disabled.
7. Test for less than 11 V between each control circuit terminal listed below and ground: Control circuit terminal 1 Control circuit terminal 2 ⇒ If 11 V or greater 7.1. Test the following circuits for a short to voltage: DTC B0070 = Circuit 3481 and circuit 3482 DTC B00013 = Circuit 3479 and circuit 3480 ⇒ If a short to voltage is found, repair the fault on the circuit. ⇓ If a short to voltage is not found 7.2. Replace the K36 Restraints Control Module. ⇓ If less than 11 V
8. Ignition OFF.
9. Verify the SIR system is disabled.
10. Test for greater than 25 Ω between each control circuit terminal listed below and ground: Control circuit terminal 1 Control circuit terminal 2 ⇒ If 25 Ω or less 10.1. Test the following circuits for a short to ground:. DTC B0070 = Circuit 3481 and circuit 3482 DTC B000213 = Circuit 3479 and circuit 3480 ⇒ If a short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found 10.2. Replace the K36 Restraints Control Module. ⇓ If greater than 25 Ω
11. Install a 3 A fused jumper wire between the control circuit terminals 1 and 2, ignition ON.
12. Verify the scan tool Deployment Loop Resistance parameter is less than 2 Ω. ⇒ If 2 Ω or greater
13. Verify the SIR system is disabled. 13.1. Test the following circuits for an open/high resistance: DTC B0070 = Circuit 3481 and circuit 3482 DTC B0072 = Circuit 3479 and circuit 3480 ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found 13.2. Replace the K36 Restraints Control Module. ⇓ If less than 2 Ω
14. Ignition OFF, connect the harness connector at the appropriate F113 Seat Belt Anchor Plate Tensioner, press in the CPA (if equipped) until an audible and/or tactile click is heard.
15. Ignition ON, clear DTCs. Operate the vehicle within the Conditions for Running the DTC.
16. Verify DTC B0070 or B0072 is not set. ⇒ If DTC B0070 or B0072 is set Replace the appropriate F113 Seat Belt Anchor Plate Tensioner. ⇓ If DTC B0070 or B0072 is not set
17. All OK. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. Front Seat Belt Anchor Plate Tensioner Replacement for Seat Belt Anchor Plate Tensioner replacement Control Module References for Restraints Control module replacement, programming and setup SIR/SRS Wiring Repairs