P2452 - Particulate Filter Pressure Sensor 'A'' Circuit
System
Powertrain (Engine & Gearbox)
Technical Description
The control module has detected a fault in the Particulate Filter Pressure Sensor 'A'' Circuit (P2452). The signal is below the lower threshold, typically from a short to ground or an internally shorted sensor.
Multimeter Test Points & Nominal Values
| Test Point / Component | Measurement | Nominal Target Range | Test Condition |
|---|---|---|---|
| Particulate Filter Pressure Sensor 'A'' Circuit – Signal Voltage | Voltage (V) | < 0.20 V (fault state) | Ignition ON, connector engaged |
| 5 V Reference Voltage | Voltage (V) | 4.95 - 5.05 V | Ignition ON at sensor connector |
| Sensor Ground Voltage Drop | Voltage (V) | < 0.05 V (< 50 mV) | Under load to chassis ground |
| Signal Wire Continuity | Resistance (Ω) | < 0.5 Ω (Open = OL) | Disconnected harness between sensor and ECM |
Ignition ON, connector engaged
Ignition ON at sensor connector
Under load to chassis ground
Disconnected harness between sensor and ECM
Oscilloscope Waveform Analysis
100 ms/div, 1 V/divPossible Causes
Short to ground on the signal wire or an internal short circuit within Particulate Filter Pressure Sensor 'A'' Circuit
Channel A:Verify dedicated wiring pins and signal pair for circuit A against the schematic.
Chafed or pinched wiring harness along the signal path to Particulate Filter Pressure Sensor 'A'' Circuit
Poor ground connection or excessive voltage drop (> 0.1 V) at the ground point for Particulate Filter Pressure Sensor 'A'' Circuit
Defective internal output driver or reference circuit in the control module for Particulate Filter Pressure Sensor 'A'' Circuit
Symptoms
4
Recommended Solution
Compare signal voltage and resistance between circuit A and companion circuit B at module connector.
Measure signal wire resistance to chassis ground with connector unplugged (must exceed 10 kΩ; low reading confirms short to ground).
Verify loaded supply voltage and harness terminal pins at Particulate Filter Pressure Sensor 'A'' Circuit.
Check circuit continuity and ground-side voltage drop (< 0.05 V) for Particulate Filter Pressure Sensor 'A'' Circuit.
Unplug the sensor:the signal must swing to a known rail. Replace the sensor or repair the wiring based on the result.
Mechanic's Tip
Always run a loaded voltage-drop test on the sensor ground with ignition ON. A drop above 0.1 V shifts the whole signal and tricks the module into setting sensor codes on a good sensor.
Common Combinations
Related Fault Codes
Exhaust Temperature Too Low For Particulate Filter Regeneration (Bank 2)
Oxygen Sensor (O2) Signals Swapped Bank 2 Sensor '2' / Bank 2 Sensor '3'
Evaporative Emission System (EVAP) Leak Detection Pump Pressure Sensor Range/Performance
Exhaust Gas Temperature Sensor (EGT) Circuit (Bank 1 Sensor '3')