DTC P1437: A/C Evaporator Temperature (A/CET) Circuit High Input
WARNING: This page does not describe the selected car, but rather 32 other vehicles, including the 2005 Mercury Sable, 2005 Mercury Mountaineer, 2005 Mercury Monterey, 2005 Mercury Montego, and 2005 Mercury Mariner. However, it is still accessible from the selected car via links, so may be relevant.
P1437 - A/C EVAPORATOR TEMPERATURE (A/CET) CIRCUIT HIGH INPUT
| Description: | Indicates the A/CET signal input was greater than the self-test minimum. The self-test maximum is 4.5 volts. | ||
| Possible Causes: |
|
||
| Diagnostic Aids: | The powertrain control module (PCM) sources a low current 5 volt reference on the A/CET circuit (this voltage can be measured with the sensor disconnected). As the A/C evaporator air temperature changes, the A/CET circuit resistance to SIG RTN (ground) changes (which changes the voltage the PCM detects). When the A/CET signal is detected above the self-test maximum, check for open circuits (A/CET or SIG RTN), which would cause the voltage to remain high. Although not as probable, also check for a short to voltage (VREF). | ||
| Application | Key On Engine Off | Key On Engine Running | Continuous Memory |
| All | GO to DJ: Air Conditioner Evaporator Temperature (ACET) Sensor STEP DJ1. | GO to DJ: Air Conditioner Evaporator Temperature (ACET) Sensor STEP DJ1. | GO to DJ: Air Conditioner Evaporator Temperature (ACET) Sensor STEP DJ9. |