P1437 Isuzu A/C Evaporator Air Temperature Circuit High

P1437 Isuzu A/C Evaporator Air Temperature Circuit High

Possible causes
  • ACET circuit open.
  • SIG RTN circuit open to the ACET sensor.
  • ACET circuit short to power (VREF).
  • Damaged ACET sensor.
  • Damaged PCM.
  • 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 Isuzu Description

    Indicates the ACET signal input was greater than the self-test maximum. The self-test maximum is 4.5 volts.

    Isuzu Vehicle:2013 Isuzu,2012 Isuzu,2011 Isuzu,2010 Isuzu,2009 Isuzu,2008 Isuzu,2007 Isuzu,2006 Isuzu,2005 Isuzu,2004 Isuzu,2003 Isuzu,2002 Isuzu,2001 Isuzu,2000 Isuzu,1999 Isuzu,1998 Isuzu,1997 Isuzu,1996 Isuzu,Isuzu Rodeo,Isuzu Trooper,Isuzu Ascender
    CategoriesUncategorized