B1944 OBD-II Trouble Code: Airbag Crash Sensor #1 Ground Circuit Open

B1944 code definition

A B1944 code means that the vehicle’s onboard diagnostic system has detected a discrepancy in the airbag circuit that is consistent with a poor ground on the #1 sensor, and has registered a trouble code.

What the B1944 code means

Airbag systems are designed to perform self-diagnostics. In the event of a B1944 code, voltages are off spec and indicate a poor ground in the system, registering a trouble code as part of the self-diagnostic process.

What causes the B1944 code?

• Open ground circuit in #1 crash sensor

What are the symptoms of the B1944 code?

• Flashing or illuminated airbag lamp on dash

How does a mechanic diagnose the B1943 code?

• Using a good quality code reader/scanner, check for any airbag-related trouble codes. B1942. B1941, B1943 and B1945 may accompany this trouble code.
• A factory wiring diagram will also be necessary for this diagnosis and repair.
• With the ignition in ON position and headlamp switch OFF, connect the scanner and check for trouble codes.
• Locate left front impact sensor. Check connectors, wiring and crimps for an intermittent problem. Perform a wiggle test. Check for any dirt, corrosion, damage or other physical problems with sensor, wiring, terminals and connectors.
• Disconnect air bag diagnostic monitor and check resistance on terminals. Measure resistance of Pin C2-21, Circuit 6/18 (p/lg) to ground. NOTE: disconnecting the diagnostic monitor disables the entire airbag system.
• If resistance is less than 3 ohms, remove the sensor’s mounting screws. Clean the mounting surface of sensor and chassis, reinstall sensor and tighten screws to spec.
  
• If resistance is greater than 3 ohms, look for open circuit or high resistance in Circuit 618 (p/lg) and inspect all interconnections, including wire crimps.
• Measure resistance between the sensor connector’s pink/orange and yellow/white wires.
• Resistance should be less than 3 ohms. Locate and repair any open circuits found in #617 or #624.
• If resistance is greater than 2 ohms, replace entire left front impact sensor.
• Clear diagnostic codes and test drive vehicle to see if codes return.

Common mistakes when diagnosing the B1944 code

As with many codes, technicians often jump ahead on a B1944 code without doing a proper process of elimination and end up replacing parts unnecessarily. A poor reference ground can lead to a false B1944 reading, prompting unnecessary repairs.

How serious is the B1944 code?

A B1944 code can result in the airbag not deploying in the event of a collision.

What repairs can fix the B1944 code?

• Replacement of left front crash sensor
• Replace/repair of wiring and connectors
• Repair of open circuit in crash sensor
• Replacement of module
• Locating and repairing short in circuit for crash sensor

Additional comments for consideration regarding the B1944 code

On many Ford vehicles, the air bag warning light will flash to alert the driver to a problem. The light will flash an indication of the code itself. In this case, it would flash four times, followed by a pause, followed by four flashes to denote 44.

Any airbag-related work is complex and might be best left up to a professional. Accidental deployment of the airbag can result in serious injury.

Need help with a B1944 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.