What does it mean?
B1672 is a Body (airbags, seat belts, body electronics) fault code. It indicates: APT Sensor Fault – CAN Signal .
Symptoms
- Noticeable loss of engine power or a limp mode with limited throttle response
- Cruise control and any speed limiter functions are disabled
- Warning lamps in the cluster together with faults stored in several modules
- Rough or unstable idle and hesitation when setting off
- Automatic stop and start, where fitted, no longer operates
- Communication faults recorded in other modules at the same time
Likely causes
- Faulty accelerator pedal position sensor, or a pedal unit with a worn or contaminated track
- Water or dirt in the accelerator pedal connector, which sits low in the footwell
- Damaged wiring between the pedal sensor and the engine control module, including chafing under the carpet
- The transmitting control module has its own pedal fault stored and stops broadcasting a valid value
- Interruption or corrosion in the network wiring so the message never reaches the receiving module
- Low system voltage or a poor module ground causing dropped messages
- Incorrect module configuration or software after a replacement or a retrofit
How to fix it
- Scan every module and note which ones report communication or pedal faults; the module storing the original pedal code leads the diagnosis
- Look at pedal position on live data and check that both sensor tracks rise smoothly from rest to full travel with no dropouts
- Inspect the pedal connector for moisture, corrosion and loose terminals, and check the harness under the carpet
- Measure the reference voltage, ground and both signal wires at the pedal sensor with the ignition on
- Check the network wiring for the receiving module, including connector corrosion and any recently added accessory tapped into the bus
- Verify battery voltage and module grounds, because a weak supply causes dropped messages that look like sensor faults
- Repair the wiring or replace the pedal sensor as proven by measurement, then clear the codes and confirm the message is present in all modules