Diagnostic Aids
WARNING: This page does not describe the selected car, but rather 32 other vehicles, including the 2003 Mercury Sable, 2003 Mercury Mountaineer, 2003 Mercury Marauder, 2003 Mercury Grand Marquis, and 2003 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.
Perform this test when directed by QUICK TEST. This system test is intended to diagnose:
- Barometric Pressure (BARO) Sensor
- Wiring Harness Circuits (BARO SIG, SIG RTN & VREF)
- Powertrain Control Module (PCM)
VREF voltage should be 4-6 volts. BARO PID reading is in frequency/volts.
BARO SENSOR SPECIFICATIONS
| In. Hg (kPa) | Frequency (Volts) | Altitude Above Sea Level (Feet) |
|---|---|---|
| 3.5 (11.8) | 0.15 | N/A |
| 5 (16.9) | 0.40 | N/A |
| 10 (33.8) | 1.25 | N/A |
| 15 (50.7) | 2.10 | 14,000 |
| 20 (67.5) | 2.90 | 10,000 |
| 21 (70.9) | 3.10 | 9000 |
| 22 (74.3) | 3.30 | 8000 |
| 23 (77.7) | 3.50 | 7000 |
| 24 (81.1) | 3.62 | 6000 |
| 25 (84.4) | 3.80 | 5000 |
| 26 (87.8) | 4.00 | 4000 |
| 27 (91.2) | 4.14 | 3000 |
| 28 (94.6) | 4.30 | 2000 |
| 29 (97.9) | 4.50 | 1000 |