Diagnostic Aids
WARNING: This page is about a different variant/trim than selected.
- If DTC P0105 is also set, a short to voltage on the 5-volt reference circuit may exist.
- The A/C pressure sensor, the FTP sensor and the throttle position (TP) sensor are all tied to the same 5-volt reference source.
- To locate an intermittent problem, use the scan tool to monitor FTP sensor voltage with the ignition ON, the engine OFF. Wiggling wires while watching for a change in FTP sensor voltage may locate the area where an open or a short to voltage in the wiring could lie.
- If DTC P0651 is also set, diagnose that DTC first.
- For intermittent conditions, refer to Testing for Intermittent Conditions and Poor Connections .
- The signal voltage with the fuel cap OFF should read between 1.30-1.70 volts, which represents atmospheric pressure or 0 inches of vacuum.
- Inaccurate readings will occur if resistance measurements are taken on a FTP sensor. The FTP sensor contains an internal amplifier circuit that requires applied voltage to function properly.
DTC P0453
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) 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 |
| 2 |
|
4.3 V | Go to Step 4 | Go to Step 3 |
| 3 |
|
- | Go to Step 4 | Go to Diagnostic Aids |
| 4 |
|
0.2 V | Go to Step 6 | Go to Step 5 |
| 5 | Measure the voltage of the FTP sensor 5-volt reference circuit with a DMM. Refer to Circuit Testing
. Is the voltage within the specified value? |
4.8-5.2 V | Go to Step 9 | Go to Step 10 |
| 6 | Test the FTP signal circuit for a short to voltage or for a short to a 5-volt reference circuit. Refer to Circuit Testing
and Wiring Repairs
. Did you find and correct the condition? |
- | Go to Step 13 | Go to Step 12 |
| 7 | Test the FTP low reference for high resistance and an open. Refer to Circuit Testing
and Wiring Repairs
. Did you find and correct the condition? |
- | Go to Step 13 | Go to Step 8 |
| 8 | Test for an intermittent and for a poor connection at the control module. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
. Did you find and correct the condition? |
- | Go to Step 13 | Go to Step 12 |
| 9 | Test for an intermittent and for a poor connection at the FTP sensor. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
. Did you find and correct the condition? |
- | Go to Step 13 | Go to Step 11 |
| 10 | Repair the short to voltage in the FTP 5-volt reference circuit. Refer to Wiring Repairs
. Did you complete the repair? |
- | Go to Step 13 | - |
| 11 | Replace the FTP sensor. Refer to Fuel Tank Pressure Sensor Replacement
. Did you complete the replacement? |
- | Go to Step 13 | - |
| 12 | Replace the engine control module (ECM). Refer to Control Module References
for replacement, setup, and programming. Did you complete the replacement? |
- | Go to Step 13 | - |
| 13 |
|
- | Go to Step 2 | Go to Step 14 |
| 14 | 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 | System OK |