P0453
DTC P0451-P0453
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provide an overview of each diagnostic category.
DTC Descriptors
DTC P0451
- Fuel Tank Pressure (FTP) Sensor Performance
DTC P0452
- Fuel Tank Pressure (FTP) Sensor Circuit Low Voltage
DTC P0453
- Fuel Tank Pressure (FTP) Sensor Circuit High Voltage
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
The FTP sensor measures air pressure or vacuum in the evaporative emission (EVAP) system. The engine control module (ECM) supplies a 5 V reference and a low reference circuit to the FTP sensor. The FTP sensor signal voltage varies depending on EVAP system pressure or vacuum.
If the average difference between the FTP sensor reading and EVAP leak detection pump pressure sensor reading is greater than 0.747 kPa (0.11 psi) after 5 seconds then an FTP sensor correlation failure has been detected and the DTC fails.
Conditions for Running the DTC
Note: These tests run when the propulsion system is ON or OFF.
P0451
Condition 1: Propulsion System Not Active
Note: There are three possible time windows for this test to run. Up to that point and through this time period the propulsion system must not be active. These time windows are: 5.0, 7.0 or 9.5 hours.
* The barometric pressure (BARO) is greater than 70 kPa (10 psi), but less than 110 kPa (16 psi).
* The fuel level is between 10 % and 90 %.
* The engine coolant temperature (ECT) is less than 40°C (104°F).
* The intake air temperature (IAT) is greater than 4°C (39°F) but less than 45°C (113°F).
Note: The 10 and 17 hours mentioned below does not apply if a code clear is performed. This test will run immediately after a code clear, if all other conditions are met.
* The battery voltage is greater than 10 volts.
* Vehicle speed is less than 1.6 km/h (1 MPH).
If any of these conditions occur this test is aborted.
* Key up during test
* Refueling request button pressed
* Service bay test active
* Device control exceeds 0.5 seconds
* No Active DTC's P0101, P0102, P0103, P0106, P0107, P0108, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0119, P0121, P0122, P0123, P0128, P012B, P012C, P012D, P0222, P0223, P0449, P0452, P0453, P0461, P0462, P0463, P0498, P0499, P0502, P0503, P06E4, P06E4, P0722, P0723, P1221, P1459, P145A, P2066, P2067, P2068, P2400, P2401, P2402, P2418, P2419, P2420, U0140, U182D, U0073, U0074, P2537, P2610.
* No Active DTC's P1458 or P145D when test failed this key on.
Condition 2: Propulsion System Active and Engine ON
* The barometric pressure (BARO) is greater than 70 kPa (10 psi), but less than 110 kPa (16 psi).
* The outside air temperature (OAT) greater than 4°C (39°F), but less than 35°C (102°F).
* The engine is running.
* Run/crank voltage is greater than 11 volts.
* Purge is not enabled.
If any of these conditions occur this test is aborted.
* Refueling request button pressed
* Device control exceeds 0.5 seconds
* No Active DTC's P0068, P0071, P0072, P0073, P010C, P010D, P0101, P0102, P0103, P0106, P0107, P0108, P0111, P0112, P0113, P0114, P012B, P012C, P012D,P0121, P0122, P0123, P0222, P0223, P0442, P0443, P0449, P0452, P0453, P0455, P0458, P0459, P0498, P0499, P0502, P0503, P0722, P0723, P0606, P1104, P1221, P145A, P145D, P145E, P1458, P1459, P16F3, P2100, P2101, P2102, P2103, P2400, P2401, P2402, P2418, P2419, P2420, P2422, P2450.
P0452 and P0453
These DTC's run continually, propulsion system ON or OFF.
Conditions for Setting the DTC
P0451
* This DTC will execute with propulsion system ON or OFF.
* A determination check is performed to find if the FTP and EVAP leak detection pump sensor are either in or out of a readable range. Then, a correlation check is performed between these sensors.
* Operates when the EVAP leak detection pump sensor thinks the FTP sensor is in a readable range.
* If the average difference between the FTP sensor reading and EVAP leak detection pump pressure sensor reading is greater than 0.747 kPa (0.11 psi) after 5 seconds, then a FTP sensor correlation failure has been detected and the DTC fails.
P0452
The FTP sensor voltage is less than 0.15 V for more than 8 s.
P0453
The FTP sensor voltage is more than 4.85 V for more than 8 s.
Action Taken When the DTC Sets
DTCs P0451, P0452 and P0453 are Type B DTCs.
Conditions for Clearing the DTC
DTCs P0451, P0452 and P0453 are Type B DTCs.
Diagnostic Aids
* A restriction in the EVAP canister or vent lines that keeps the FTP and EVAP leak detection pump sensor from comparing each others value.
* Since this is a sealed system there could be a pressure or vacuum.
* Ensure that the reference port on the FTP sensor is unobstructed.
* Scan tool output controls, snapshot, and the plot function can help detect erratic sensor operation.
Reference Information
Schematic Reference
Engine Controls Schematics [1][2]Electrical Diagrams
Description and Operation
Evaporative Emission Control System Description Evaporative Emission Control System Description
Hybrid Modes of Operation Description Hybrid Modes of Operation Description
Connector End View Reference
Component Connector End Views Hybrid/EV Battery Pack X1 A4
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References for scan tool information
Special Tools
EN 41413-200 - Evaporative Emissions System Tester
For equivalent regional tools, refer to Special Tools (Diagnostic Tools) Special Tools (Diagnostic Tools).
Circuit/System Verification
P0451
1. Service Mode active, read the EVAP leak detection pump sensor and record this. This is equivalent to a BARO reading. Now read and record the FTP value.
2. If the FTP is reading 0 kPa (0 psi). you need to add 1-2 kPa (0.15-0.29 psi) pressure or vacuum to the EVAP system.
3. If the FTP reading is 15 in H2o or 3.73 kPa (0.54 psi) (+ or -) or greater, you will need to reduce the pressure or vacuum down 1-2 kPa (0.15-0.29 psi) before proceeding as this is outside the readable range of the FTP sensor.
Note: The order of these steps is important. If not followed properly you will be bleeding off any pressure or vacuum in the system and not see any change in the EVAP leak detection pump sensor.
4. Using device control, command the switch valve to the pump position then open the vent valve.
5. See table under Circuit Description for example values.
P0452 and P0453
1. Request a refueling event. This opens the vent valve to bleed off any pressure or vacuum.
2. Remove the fuel cap.
3. Service Mode active.
4. Observe the scan tool FTP sensor parameter.
5. The FTP sensor parameter should be 2.26-2.41 V at 0 kPa (0 psi).
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector X350 body harness to EVAP harness.
2. Ignition OFF, ensure that the ECM completely powers down and test for less than 5 ohm between the X350 body harness to EVAP harness low reference circuit male side terminal C and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
3. Service Mode active, test for 4.8-5.2 V between the X350 body harness to EVAP harness 5 V reference circuit male side terminal D and ground.
• If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
• If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
4. Verify the scan tool FTP sensor parameter is less than 0.2 V.
• If greater than the specified range, test the X350 body harness to EVAP harness signal circuit male side terminal E for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
5. Install a 3 A fused jumper wire at the X350 body harness to EVAP harness signal circuit male side terminal E and the 5 V reference circuit male side terminal D. Verify the scan tool FTP sensor parameter is greater than 4.7 V.
• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
6. If all circuits test normal, replace the B150 fuel tank pressure sensor and connect the harness connector at B150 fuel tank pressure sensor.
7. Verify the DTC does not reset.
• If the DTC resets, replace the harness between X350 body harness to EVAP harness and B150 fuel tank pressure sensor.
Repair Instructions
* For DTC P0452 or P0453, perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* For DTC P0451, clear DTCs with a scan tool.
* Fuel Tank Pressure Sensor Replacement Service and Repair
* Control Module References Control Module References for ECM replacement, setup, and programming