Description - High And Low Limits
WARNING: This page is about a different car, the 2004 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.
The PCM compares input signal voltages from each input device with established high and low limits for the device. If the input voltage is not within limits and other criteria are met, the PCM stores a diagnostic trouble code in memory. Other diagnostic trouble code criteria might include engine RPM limits or input voltages from other sensors or switches that must be present before verifying a diagnostic trouble code condition.