• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
Exhaust Differential Pressure Sensor - 5-Volt Reference | P0117, P0652, P2454 | P2453 | P2455 | P0118, P0653, P2455 | P2453 |
Exhaust Differential Pressure Sensor Signal | P2454 | P2453 | P2454 | P2455 | P2453 |
Exhaust Differential Pressure Sensor Low Reference | -- | P2453 | P2455 | -- | P2453 |
Circuit | Short to Ground | Open | Short to Voltage |
---|---|---|---|
Operating Conditions: Ignition ON, Engine OFF Parameter Normal Range: -1.0 kPa to +0.3 kPa | |||
Exhaust Differential Pressure Sensor - 5-Volt Reference | -14.5 kPa | -14.5 kPa | 99.9 kPa |
Exhaust Differential Pressure Sensor Signal | -14.5 kPa | 99.9 kPa | 99.9 kPa |
Exhaust Differential Pressure Sensor Low Reference | -- | 99.9 kPa | -- |
The exhaust differential pressure sensor measures the pressure difference across the inlet and outlet of the diesel particulate filter (DPF). The pressure difference across the DPF increases as captured particulates in the DPF increases. A diaphragm within the exhaust differential pressure sensor is displaced by the pressures change that occur from particulate matter loading. The sensor translates this action into electrical resistance. The engine control module (ECM) supplies a 5-volt reference circuit and a ground on the low reference circuit. The exhaust differential pressure sensor provides a signal voltage to the ECM, relative to the back pressure as a function of exhaust flow, DPF temperature, and DPF soot loading. The ECM converts the signal voltage input to a pressure value.
• | The engine is running for greater than 4 seconds. |
• | The ignition 1 voltage is greater than 11 volts. |
• | The above conditions are met for greater than 2 seconds. |
• | DTCs P2454 and P2455 run continuously within the above enabling conditions. |
The ECM detects that the exhaust pressure differential sensor voltage is less than 0.93 volt for 2 seconds.
The ECM detects that the exhaust pressure differential sensor voltage is greater than 4.1 volts for 2 seconds.
DTCs P2454 and P2455 are Type A DTCs.
DTCs P2454 and P2455 are Type A DTCs.
• | Inspect the exhaust differential pressure sensor terminals for corrosion. |
• | Inspect the harness connector terminals for proper tension. |
Diesel Particulate Filter (DPF) System Description
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
• | J 23738-A Mityvac |
• | J 35555 Metal Mityvac |
⇒ | If the DTCs are set, refer to DTC P0652 or P0653. |
• | Damaged components |
• | Loose or improper installation |
• | Leaks or restrictions in the exhaust differential pressure lines or hoses. The pressure lines should have a continuous downward gradient, without sharp bends, or kinks from the pressure sensor to the exhaust filter assembly. |
Important: Perform the Repair Verification after completing the Circuit/System Testing.
• | A loose fit |
• | Any cracking |
• | An internal restriction |
• | Incorrect routing--Ensure the smaller diameter pressure line is connected to the front of the DPF, and to the smaller port of the differential pressure sensor. |
⇒ | If a condition is found, repair or replace the differential pressure lines as necessary. |
⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM. |
⇒ | If less than the specified range, test the signal circuit terminal 2 for a short to ground. If the circuit tests normal, replace the ECM. |
⇒ | If greater than the specified range, test the signal circuit terminal 2 for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM. |
Important: You must perform the Circuit/System Testing in order to verify the integrity of the exhaust pressure differential sensor circuits before proceeding with the Component Testing.
⇒ | If the voltage is erratic, replace the exhaust differential pressure sensor. |
• | Control Module References for ECM replacement, setup, and programming |