P1457-FUEL TANK PRESSURE SENSOR CIRCUIT HIGH
For a complete wiring diagram, refer to the Wiring Information.
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When Monitored:
Ignition Key on. Battery voltage greater than 10.38 volts.
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Set Condition:
The Fuel Tank Pressure Sensor (FTP) signal voltage is greater than the maximum allowable voltage. One trip fault. Three good trips to turn off the MIL.
POSSIBLE CAUSES |
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| FTP SIGNAL CIRCUIT SHORTED TO VOLTAGE |
| FTP SIGNAL CIRCUIT OPEN/HIGH RESISTANCE |
| FTP SIGNAL CIRCUIT SHORTED TO THE 5-VOLT SUPPLY CIRCUIT |
| SENSOR GROUND CIRCUIT OPEN/HIGH RESISTANCE |
| FUEL TANK PRESSURE (FTP) SENSOR |
| POWERTRAIN CONTROL MODULE (PCM) |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
| 1. | Start the engine and allow it to reach normal operating temperature. |
When the engine is operating, do
not stand in direct line with the fan. Do not put your hands near
the pulleys, belts or fan. Do not wear loose clothing. Failure to
follow these instructions may result in possible serious or fatal
injury.
WARNING:
| NOTE: | Diagnose and repair any system voltage or sensor supply voltage DTCs before continuing with this test. |
| 2. | With the scan tool, select View DTCs. |
Is the DTC Active at this time
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
2. CHECK THE (N7) FTP SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
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| 1. | Turn the ignition off. |
| 2. | Disconnect the FTP Sensor harness connector. |
| 3. | Turn the ignition on. |
| 4. | Measure the voltage on the (N7) FTP Signal circuit at the FTP harness connector. |
Is there any voltage reading above 5.2 volts?
Yes
- Repair the (N7) FTP Signal circuit for a short to voltage.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
- Go To 3
3. CHECK THE (N7) FTP SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
| 1. | Turn the ignition off. |
| 2. | Disconnect the PCM C1 harness connector. |
Do not probe the PCM harness connectors. Probing the PCM harness
connectors will damage the PCM terminals resulting in poor terminal
to pin connection. Install the GPEC Diagnostic Adaptor to perform
the diagnosis.
CAUTION:
| 3. | Connect the Adapter, GPEC Diagnostic 10436 . |
| 4. | Measure the resistance of the (N7) FTP Signal circuit between the FTP harness connector and the GPEC Adaptor. |
Is the resistance below 5.0 Ohms?
Yes
- Go To 4
No
- Repair the (N7) FTP Signal circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
4. CHECK FOR THE (N7) FTP SIGNAL CIRCUIT SHORTED TO THE (K859) 5-VOLT SUPPLY CIRCUIT
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| 1. | Measure the resistance between the (N7) FTP Signal circuit and the (K859) 5-Volt Supply circuit at the FTP harness connector. |
Is the resistance above 10k Ohms?
Yes
- Go To 5
No
- Repair the short between the (K859) 5-Volt Supply circuit and the (N7) FTP Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
5. CHECK THE SENSOR GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE
| 1. | Measure the resistance of the (K917) Sensor Ground circuit from the FTP harness connector to the appropriate terminal the GPEC Adaptor. |
Is the resistance below 5.0 Ohms?
Yes
- Go To 6
No
- Repair the open in the (K917) Sensor ground circuit.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
 |
| 1. | Turn the ignition off. |
| 2. | Reconnect the PCM C1 harness connector. |
| 3. | Connect a jumper between the (N7) FTP Signal circuit and the (K917) Sensor Ground circuit in the Sensor harness connector. |
| 4. | Turn the ignition on. |
| 5. | With the scan tool, monitor the FTP voltage. |
| NOTE: | The sensor voltage should be approximately 0.0 volts (plus or minus .1 volts) with the jumper in place. |
Does the scan tool display the voltage as described above?
Yes
- Verify that there is good pin to terminal contact in the FTP and Powertrain Control Module connectors. Replace the FTP if no problems were found with the connectors.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
- Go To 7
7. POWERTRAIN CONTROL MODULE (PCM)
| 1. | Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the FTP and the Powertrain Control Module (PCM). |
| 2. | Look for any chafed, pierced, pinched or partially broken wires. |
| 3. | Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the FTP and Powertrain Control Module connectors. |
| 4. | Perform any Technical Service Bulletins that may apply. |
Were there any problems found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
- Replace and program the Powertrain Control Module in accordance with the Service Information. (Refer to 08 - Electrical/8E - Electronic Control Modules/MODULE, Powertrain Control - Removal) .
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).