OBD Guide

B1939

Air Bag Passenger Pressure Switch Circuit Short To Ground Fault

B1939 is an OBD-II diagnostic trouble code meaning: Air Bag Passenger Pressure Switch Circuit Short To Ground Fault. Common causes: damage to the pressure sensor wiring harness, short circuit to ground in the sensor circuit. Estimated repair cost: $56–167.

Severity
⚠️ Medium
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$56–167 (est.)

Symptoms

  • Airbag light (SRS) is on
  • Security error message on dashboard
  • The passenger airbag may not deploy in a crash.

Causes

  • Damage to the pressure sensor wiring harness
  • Short circuit to ground in the sensor circuit
  • Corrosion of sensor contacts or connectors
  • Pressure sensor malfunction

How to Fix

  1. Visually inspect the sensor wiring harness for damage.
  2. Check the continuity of the sensor circuit using a multimeter
  3. Clean connector contacts from corrosion
  4. Replace pressure sensor if necessary
  5. Reset the error code and check the system

Related codes

FAQ

What does the B1939 code mean?

B1939 is an OBD-II diagnostic trouble code that indicates: Air Bag Passenger Pressure Switch Circuit Short To Ground Fault

What causes a B1939 error code?

The most common causes of B1939 include: Damage to the pressure sensor wiring harness; Short circuit to ground in the sensor circuit; Corrosion of sensor contacts or connectors; Pressure sensor malfunction.

How do I fix a B1939 diagnostic trouble code?

To fix B1939: Visually inspect the sensor wiring harness for damage.. Check the continuity of the sensor circuit using a multimeter. Clean connector contacts from corrosion. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B1939?

Do not drive — repair immediately

How much does it cost to fix B1939?

The estimated repair cost for B1939 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat