P1437 BMW A/C Evaporator Air Temperature Circuit High
Possible causes
Tech description
The PCM sources a low current 5 volts on the ACET circuit (this voltage can be measured with the sensor disconnected). As the A/C evaporator air temperature changes, the ACET circuit resistance to SIG RTN (ground) changes (which changes the voltage the PCM detects). When the ACET signal is detected above the self-test maximum, check for open cirucits (ACET or SIG RTN), which would cause the voltage to remain high. Although not as probable, also check for a short to power (VREF).
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P1437 BMW Description
Indicates the ACET signal input was greater than the self-test maximum. The self-test maximum is 4.5 volts.
BMW Vehicle:BMW F650GS,BMW F800S,BMW F800ST,BMW G450X,BMW G650 Xmoto,BMW R1200GS,BMW R1200R,BMW R1200RT,BMW R1200S,BMW K1200LT,BMW K1300GT,BMW K1300R,BMW K1300S,BMW K1600GT and K1600GTL,BMW S1000RR,BMW E36/5,BMW E36/7,BMW E36/8,BMW E38,BMW E38/2,BMW E38/3,BMW E39,BMW E46/5,BMW E46/4,BMW E46/3,BMW E46/2,BMW E46/C,BMW E52,BMW E53,BMW E60,BMW E61,BMW E62,BMW E63,BMW E64,BMW E65,BMW E66,BMW E67,BMW E68,BMW E70,BMW E71,BMW E72,BMW E81,BMW E82,BMW E83,BMW E84,BMW E85,BMW E86,BMW E87,BMW E88,BMW E89,BMW E90,BMW E91,BMW E92,BMW E93,BMW F01,BMW F02,BMW F03,BMW F04,BMW F06,BMW F07,BMW F10,BMW F11,BMW F12,BMW F13,BMW F15,BMW F18,BMW F20,BMW F21,BMW F22,BMW F25,BMW F26,BMW F30,BMW F31,BMW F32,BMW F33,BMW F34,BMW F35,BMW F36,BMW F80,BMW F82