B1B18

Symptoms

• Airbag warning light on instrument panel is on
• Side curtain airbags do not deploy in crash test
• Periodic flashing of the SRS lamp when driving
• There may be visible damage to the wiring harness near the door.
• During diagnostics, error B1B18 is detected

Causes

• Broken or frayed wire in the left door harness
• Oxidation or corrosion of squib connector contacts
• Loose or disconnected wiring harness connector
• Malfunction of the squib itself (internal break)
• Damage to the connector due to moisture or mechanical impact
• SRS control module malfunction
• Problem in the main power supply circuit of the security system

How to Fix

1. Connect a diagnostic scanner and record the full error text
2. Disconnect the negative battery terminal for 15 minutes to reset the error
3. Conduct a visual inspection of the wiring harness in the left door area for damage, insulation cracks or chafing.
4. Check the squib connectors and connecting connectors for oxidation and corrosion; clean contacts if necessary
5. Make sure the connection of the squib connector is secure.
6. Measure the resistance of the squib with an ohmmeter (usually 1.5-3 Ohms) and check the continuity of the circuit
7. Check the voltage at the squib connector with the ignition on (should be close to the battery voltage)
8. If a damaged wire is found, replace the left door wiring harness
9. If the squib is faulty, replace it as an assembly.
10. Clear the diagnostic code and check that the error disappears

Related codes

FAQ