P1464
Heated Catalyst Battery Temperature Sensor 2 Electrical.
- BMW
- Powertrain
- Manufacturer code
- Low severity
How this code is built
- P
- SystemPowertrain
- 1
- Defined byThe manufacturer
- 4
- AreaAuxiliary emission controls
- 64
- FaultThe specific fault in that area
What it means
On BMW, P1464 is defined as an electrical fault in the circuit of temperature sensor 2 associated with the heated catalyst battery. The engine control unit saw a signal from this circuit that was outside the expected range, such as a short, an open circuit or an implausible voltage. Where this sensor sits and what it monitors depends on the model and engine, so confirm it against manufacturer data for the exact vehicle.
Symptoms
- Engine warning light on
- Fault stored with no obvious change in driveability
- Possible slower catalyst warm-up or higher cold-start emissions
- Emissions-related readiness monitors not completing
- Intermittent warning light that returns after clearing
Possible causes
- Damaged, chafed or corroded wiring to the temperature sensorlikely
- Poor connection or water ingress at the sensor or control unit connectorlikely
- Faulty temperature sensor with an internal open or short circuitpossible
- Fault in the heated catalyst battery or its supply and earth connectionspossible
- Heat damage to the harness near the exhaustpossible
- Fault inside the engine control unitrare
How to diagnose
- Read all stored and pending codes and the freeze frame data. Note any related heated catalyst or catalyst codes.
- Check manufacturer data to confirm where sensor 2 is fitted on this model and engine, and what the circuit pin-out is.
- Visually inspect the sensor wiring and connectors for chafing, heat damage, corrosion, moisture and loose pins.
- Check the battery voltage and the supply and earth connections to the heated catalyst circuit.
- With the ignition off, test the sensor circuit for continuity, short to earth and short to supply against the wiring diagram.
- Measure the sensor resistance or live reading and compare it with the specification, ideally with the engine cold and then warm.
- Wiggle-test the harness with live data on screen to find intermittent faults.
- If the wiring and sensor test good, check the control unit connector and power and earth supplies before suspecting the control unit.
How to fix
- Repair or replace the damaged wiring section, using proper heat-resistant, sealed repairs.
- Clean, re-seat or replace the corroded or loose connector terminals.
- Replace the temperature sensor if it fails the resistance or signal check.
- Repair the supply or earth fault affecting the heated catalyst circuit.
- Replace or repair the control unit only after all the wiring and sensor checks have been completed and confirmed.
Can I keep driving?
The car can usually be driven normally while you book it in for diagnosis. Do not leave it long, as a catalyst that is not being monitored or heated correctly can raise emissions and may lead to an MOT failure.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.