What this code means
B0020 may indicate that the SRS is seeing an open or increased resistance condition in the driver’s side airbag inflator circuit.
What the vehicle may do
- The SRS warning lamp may be on.
- Part of the restraint system strategy may be disabled while the fault is present.
Possible fault areas
- Possible driver’s side airbag inflator fault.
- Possible floor harness or circuit open.
- Possible poor connector contact at the SRS unit.
- Possible SRS unit concern.
Diagnostic path
Open and safety setup
On this 2010 to 2016 Honda CR-V, B0020 may indicate that the SRS is seeing an open or increased resistance condition in the driver’s side airbag inflator circuit. The SRS warning lamp may be on, and part of the restraint strategy may be disabled while the fault is present. Broadly, this can involve the driver’s airbag inflator, the floor harness side of the circuit, connector contact at the SRS unit, or the SRS unit itself. Before touching anything in this circuit, find out if the vehicle has been in a collision. If it has, make sure the required SRS parts were replaced with the correct new parts and installed correctly. Also use the normal SRS handling precautions, and follow the correct 12 volt battery disconnect and reconnect process.
Duplicate the fault first
Start by proving whether the fault is active. Clear the codes with the HDS. Turn the vehicle to the ON mode, wait for 10 seconds, then check codes again with the HDS. If B0020-13 comes right back, the failure is duplicated and you continue into circuit testing. If it does not come back, treat it as an intermittent at this time. If other codes are present, check what they mean first instead of chasing this one blindly.
Use the simulator to separate the airbag from the rest of the circuit
Next, isolate the driver’s airbag inflator from the harness. Turn the vehicle to OFF, disconnect the negative cable from the 12 volt battery, and wait at least 3 minutes. Disconnect the driver’s side airbag inflator 2P connector on the floor wire harness. Connect the terminals of SRS simulator lead L to the SRS inflator simulator, using the 2 Ω connectors, then connect SRS simulator lead L to the driver’s side airbag inflator 2P connector on the floor wire harness. Reconnect the negative cable to the 12 volt battery. Clear the codes with the HDS, turn the vehicle to the ON mode, wait for 10 seconds, and check codes again. If B0020-13 is still indicated, keep going to the open-wire check. If B0020-13 is no longer indicated, treat that as an open in the driver’s side airbag inflator; replace the driver’s side airbag, then clear the code.
Check the LSA circuit for an open
For the open-wire check, turn the vehicle to OFF again. Disconnect the negative cable from the 12 volt battery and wait at least 3 minutes. Disconnect SRS unit connector B, the 39P connector. Now disconnect the SRS inflator simulator from SRS simulator lead L, but leave SRS simulator lead L connected to the driver’s side airbag inflator 2P connector on the floor wire harness. Measure resistance at the SRS simulator lead L black terminal. The decision point is 1.0 Ω or less. If the measurement is 1.0 Ω or less, the LSA＋ and LSA－ wires are considered OK. At that point, look for a poor connection at SRS unit connector B and the SRS unit, or a faulty SRS unit. Before replacing the SRS unit, check the SRS unit software version with the HDS. If it is not the latest version, update the SRS unit software and retest. If the connection is OK, replace the SRS unit. If the code still does not clear after that, replace the floor wire harness. If the resistance is not 1.0 Ω or less, treat it as an open in the floor wire harness; replace the floor wire harness, then clear the code.
Verify the repair
Keep the final check separate from the component tests. After the supported repair is complete, clear the codes with the HDS, turn the vehicle to the ON mode, wait for 10 seconds, and check the SRS codes again. The takeaway is simple: duplicate B0020 first, use the simulator to separate the airbag from the harness, then use the resistance check to decide whether the circuit, connector, SRS unit, or floor harness is the next path. For more diagnostic training, visit stepdiagnostics.com.
Final check
Duplicate the fault first, isolate the airbag with the simulator, then use the circuit resistance result to choose the next diagnostic path.
For more guided automotive diagnostics, visit STEP Diagnostics.
