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Test Description

The number below refers to the step number on the diagnostic table.

  1. 2:  This step verifies that the condition is present.
  2. 8:  This step test for high resistance in the low reference circuit of the FTP sensor. The ECM must be completely powered down to obtain an accurate resistance reading. It may take up to 30 minutes for the ECM to power down after the ignition key is removed. Removal of the ECM fuse, or the PCM/ETC fuse, allows the ECM to power down completely.
P0453 Fuel Tank Pressure (FTP) Sensor Circuit High Voltage

Step Action Values Yes No
Schematic Reference:  Engine Controls Schematics 
Connector End View Reference:  Engine Control Module Connector End Views  or  Engine Controls Connector End Views 
1 Did you perform the Diagnostic System Check - Vehicle? - Go to Step 2  Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2 
  1. Turn ON the ignition, with the engine OFF.
  2. Observe the fuel tank pressure (FTP) sensor voltage parameter with a scan tool.
Is the voltage more than the specified value?		 4.6 V Go to Step 4  Go to Step 3 
3
  1. Observe the Freeze Frame/Failure Records for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition?		 - Go to Step 4  Go to Diagnostic Aids
4
  1. Remove the fuel tank cap from the fuel fill pipe.
  2. Observe the fuel tank pressure (FTP) sensor voltage parameter with a scan tool.
Is the voltage more than the specified value?		 4.6 V Go to Step 5  Go to Step 17 
5
  1. Turn OFF the ignition.
  2. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information
  3. Disconnect the fuel tank in-line harness connector.
  4. Turn ON the ignition, with the engine OFF.
  5. Observe the FTP sensor voltage parameter with a scan tool.
Is the voltage less than the specified value?		 0.1 V Go to Step 7  Go to Step 6 
6 Test the signal circuit of the FTP sensor for a short to voltage between the fuel tank harness connector and the engine control module (ECM). Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 20  Go to Step 15 
7 Measure the voltage between the 5-volt reference circuit of the FTP sensor and a good ground, with a DMM.
Is the voltage more than the specified value?		 6 V Go to Step 11  Go to Step 8 
8 
NOTE: Do NOT use a test lamp to test the continuity of the circuit. Damage to the control module may occur due to excessive current draw.
  1. Turn OFF the ignition.
  2. Remove the ECM fuse, or the PCM/ETC fuse, from the underhood electrical center.
  3. Measure the resistance from the low reference circuit of the FTP sensor to a good ground with a DMM.
Is the resistance less than the specified value?		 5 Ω Go to Step 12  Go to Step 9 
9
  1. Install the ECM fuse, or the PCM/ETC fuse, into the underhood electrical center.
  2. Turn ON the ignition with the engine OFF.
  3. Measure the voltage between the low reference circuit of the FTP sensor and a good ground with a DMM. Refer to Circuit Testing in Wiring Systems.
Is the voltage less than the specified value?		 1.0 V Go to Step 10  Go to Step 16 
10 Test the low reference circuit of the FTP sensor for an open between the fuel tank in-line harness connector and the ECM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 20  Go to Step 15 
11
IMPORTANT: The engine control module (ECM) for this engine is not equipped with 5-volt reference DTCs. The 5-volt reference circuits are internally and externally connected at the controller. Other sensors that share the 5-volt reference circuit may also have DTCs set. Disconnecting a sensor on the shared 5-volt reference circuit may isolate a shorted sensor. Review the electrical schematic and diagnose the shared circuits and sensors.
Test the 5-volt reference circuit of the FTP sensor for a short to voltage between the fuel tank in-line harness connector and the ECM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.Did you find and correct the condition?		 - Go to Step 20  Go to Step 15 
12 Test for shorted terminals and for poor connections at the fuel tank in-line harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 20  Go to Step 13 
13
  1. Remove the fuel tank. Refer to Fuel Tank Replacement .
  2. Inspect the fuel tank wiring harness for the following conditions:
    • Inspect for damaged wiring.
    • Inspect for opens or for a short to voltage in the FTP sensor harness from the fuel tank wiring harness connector to the FTP sensor.
  3. Repair as necessary. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 20  Go to Step 14 
14 Test for shorted terminals and for poor connections at the FTP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 20  Go to Step 18 
15 Test for shorted terminals and for poor connections at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 20  Go to Step 19 
16
IMPORTANT: The control module and/or the FTP sensor may be damaged if the circuit is shorted to battery positive voltage.
Repair the short to voltage in the low reference circuit of the FTP sensor. Refer to Wiring Repairs in Wiring Systems.Did you complete the repair?		 - Go to Step 20  -
17 Repair the restriction in the evaporative emission (EVAP) canister atmospheric vent pipe.
Did you complete the repair?		 - Go to Step 20  -
18 Replace the FTP sensor. Refer to Fuel Tank Pressure Sensor Replacement .
Did you complete the replacement?		 - Go to Step 20  -
19 Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.
Did you complete the replacement?		 - Go to Step 20  -
20
  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition?		 - Go to Step 2  Go to Step 21 
21 Observe the Capture Info with a scan tool.
Are there any DTCs that have not been diagnosed?		 - Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information System OK
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