What it means
The exhaust pressure sensor A circuit signal is higher than expected. Possible causes include a wiring or connector fault, a sensor fault, or a pressure-passage issue.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Exhaust pressure sensor A sends a pressure signal to the control module through its signal circuit. This code sets when that signal is higher than expected, which can happen if the signal line is open or shorted toward a power source.
Common causes
Most likely first.
- Open signal line
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
Symptoms
- Check-engine light on
- Possible reduced engine power
- Possible increased exhaust smoke
- Possible reduced fuel economy
How to diagnose it
- Record freeze-frame data and check sensor A's live reading to confirm whether the high signal is constant or intermittent.
- Inspect the sensor A connector and wiring for disconnected terminals, corrosion, broken conductors, or insulation damage.
- Trace the signal and supply wires for an open signal line or a pinched wire contacting battery voltage or another power source.
- Check the pressure tube and passage for blockage or damage and compare the reading with the conditions described in service information.
- Test sensor A's supply, ground, and signal circuits for opens and shorts using the wiring diagram and manufacturer's specification.
- If the circuit and pressure path are sound, test sensor A itself and replace it if its output remains above specification.
Common fixes
- Reconnect and secure the sensor A connector.
- Repair an open signal wire or a broken connector terminal.
- Repair wiring pinched against a power source or otherwise shorted high.
- Clear a blocked pressure passage or repair a damaged tube.
- Replace exhaust pressure sensor A if it fails testing with a sound circuit.
Can I keep driving?
If the engine runs normally, drive gently and avoid towing or hard acceleration if power or smoke changes. A signal that reads too high can interfere with exhaust controls and emissions performance, so arrange diagnosis soon.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.