Diagnostic Aids
Temperature should rise steadily to about 90°C, then stabilize. A faulty connection or an open in ground or signal circuit can result in Code 59. A skewed sensor could result in firm shifts or TCC enabled complaints. Use temperature-to-resistance table to check sensor at various levels to determine if sensor is out-of-calibration, which could result in firm shifts or TCC enable.
TEMPERATURE-TO-RESISTANCE VALUES (Measure resistance across sensor terminals)
| Temperature °F (°C) | Ohms |
|---|---|
| 212 (100) | 177 |
| 194 (90) | 241 |
| 158 (70) | 467 |
| 104 (40) | 1459 |
| 68 (20) | 3520 |
| 23 (-5) | 12,300 |
| 14 (-10) | 16,180 |
| 0 (-18) | 25,000 |
| -4 (-20) | 28,680 |
| -22 (-30) | 52,700 |
| -40 (-40) | 100,700 |