The PCM monitors the fuel tank pressure sensor signal to detect vacuum decay and excess vacuum during the enhanced EVAP diagnostic. The fuel tank pressure sensor measures the difference between the air pressure (or vacuum) in the tank and the outside air pressure. The PCM applies a 5.0 volt reference and ground to the sensor. The sensor will return a signal voltage between 0.1 and 4.9 volts. If the PCM detects a fuel tank pressure sensor signal that is excessively low, DTC P0452 will set.
The ignition is ON.
• | The fuel tank pressure sensor signal is less than 0.1 volts. |
• | The conditions is present for 5 seconds. |
• | The PCM will illuminate the MIL during the second consecutive trip in which the diagnostic test has been run and failed. |
• | The PCM will store conditions which were present when the DTC set as Freeze Frame and Fail Records data. |
• | The PCM will turn the MIL OFF during the third consecutive trip in which the diagnostic has been run and passed. |
• | The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
• | The DTC can be cleared by using the scan tool Clear Info function or by disconnecting the PCM battery feed. |
Check for the following conditions:
• | Poor connection at the PCM or Fuel Tank Pressure Sensor. |
Inspect harness connectors for backed out terminals, improper mating broken locks, improperly formed or damaged terminals, and poor terminal to wire connection. |
• | Damaged harness. |
Inspect the wiring harness for damage. If the harness appears to be OK, observe the Fuel Tank Pressure Sensor display on the scan tool while moving connectors and wiring related to the sensor. A change in the display will indicate the location of the malfunction. |
Numbers below refer to the step numbers on the Diagnostic Table.
Step | Action | Values | Yes | No |
---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic(OBD) System Check performed? | -- | ||
2 |
Is fuel tank pressure sensor voltage less than the specified value? | 0.3V | ||
3 |
Does the scan tool indicate DTC P0452 failed this ign? | -- | Go to Diagnostic Aids | |
4 |
Is fuel tank pressure sensor voltage near the specified value? | 5V | ||
5 | Using a Digital Multimeter, measure voltage between the 5 volt reference A circuit and the sensor ground circuit at the fuel tank pressure sensor harness connector. Is voltage near the specified value? | 5V | ||
6 |
Was a problem found? | -- | ||
7 |
Was a problem found? | -- | ||
8 |
Was a problem found? | -- | ||
9 |
Was a problem found? | -- | ||
10 |
Was a problem found? | -- | ||
11 | Replace the fuel tank pressure sensor. Refer to Fuel Tank Pressure Sensor Replacement . Is action complete? | -- | -- | |
Important:: The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Is action complete? | -- | -- | ||
13 |
Does the scan tool indicate DTC P0452 failed this ign? | -- | System OK |