Diagnostic Aids
If DTC P0453 is also set, a short to voltage on 5-volt reference circuit may exist. See 5-VOLT REFERENCE CIRCUIT ERROR DIAGNOSIS under SYSTEM TESTS.
DTC will set if either MAP or TP is out of range. To distinguish which one has failed, review failure records and attempt to duplicate conditions.
Check sensor and PCM electrical connection for corrosion. Using scan tool, check for a shifted MAP sensor. See MAP SENSOR VOLTAGE RANGE table. Compare this reading to a known-good vehicle with the same sensor. Readings should be within 0.4 volt.
Use scan tool to monitor TP sensor as accelerator pedal is slowly depressed. Voltage should change smoothly from 0.35 volt at closed throttle, to 4.45-4.85 volts at wide open throttle.
MAP SENSOR VOLTAGE RANGE
| Altitude (Feet) | Volts |
|---|---|
| Less Than 1000 | 3.8-5.5 |
| 1000-2000 | 3.6-5.3 |
| 2000-3000 | 3.5-5.1 |
| 3000-4000 | 3.3-5.0 |
| 4000-5000 | 3.2-4.8 |
| 5000-6000 | 3.0-4.6 |
| 6000-7000 | 2.9-4.5 |
| 7000-8000 | 2.8-4.3 |
| 8000-9000 | 2.6-4.2 |
| 9000-10,000 | 2.5-4.0 |