Standard Ignition AX27 Ambient Air Temperature Sensor

Ambient Air Temperature Sensor for GM Applications

Standard Ignition AX27 is an ambient air temperature sensor built for accurate temperature measurement and reliable HVAC system operation. It uses a bolt-on mounting style, a black housing, and a plug-in oval connector to support direct replacement service on select Buick, Cadillac, Chevrolet, and Oldsmobile vehicles.

Fits 1991-2005 Buick LeSabre, N/A; Fits 1992-2005 Buick Park Avenue, N/A; Fits 1994-2005 Cadillac DeVille, N/A; Fits 1992-2005 Pontiac Bonneville, N/A; Fits 1994-2004 Cadillac Seville, N/A; Fits 2001-2003 Oldsmobile Aurora, N/A; Fits 1995-1999 Oldsmobile Aurora, N/A; Fits 1994-2002 Cadillac Eldorado, N/A; Fits 1995-1999 Buick Riviera, N/A; Fits 1992-1999 Oldsmobile 88, N/A; Fits 1996-1999 Oldsmobile LSS, N/A; Fits 1997-1998 Chevrolet S10, N/A; Fits 1997-1998 Oldsmobile Regency, N/A; Fits 1991-1996 Oldsmobile 98, N/A; Fits 1993 Cadillac DeVille, N/A, w/o Wire; Fits 1993 Cadillac Eldorado, N/A, w/o Wire.

• Bolt-on attachment with included mounting bracket(s)
• Female oval plug-in connector with 2 blade terminals
• Black sensor housing
• Sensor only; wiring harness not included
• Direct replacement for select GM HVAC temperature sensor applications

Built for Accurate Temperature Readings

AX27 is engineered with tight thermistor response tolerances to help maintain accurate ambient air temperature measurement. Standard Ignition factory tests its air charge and manifold temperature sensors before release, and this sensor follows the same quality-focused manufacturing approach for dependable operation in service. It cross-references Four Seasons 75967 and other common replacement numbers including 5S1128 and 15-71823 for the same application. Standard Ignition AX27 is a practical choice for Buick LeSabre, Cadillac DeVille, and Pontiac Bonneville service where the ambient temperature signal affects HVAC performance.

Common Problems This Sensor Can Address

• Incorrect outside temperature display
• HVAC system responding to inaccurate ambient air data
• Faulty sensor signal from a worn or damaged unit
• Connector or terminal wear at the sensor connection point
• Service replacement on vehicles with missing or damaged original sensor

Installation Notes and Tips

Verify connector style, terminal count, and mounting location before installation. AX27 uses a female oval connector with two male blade terminals and a bolt-on design, so the existing harness and bracket arrangement must match the vehicle application. For 1993 Cadillac DeVille and 1993 Cadillac Eldorado, confirm the w/o Wire note before ordering. Inspect the connector for corrosion or looseness and make sure the sensor seats securely at the mounting point.

Quality Assurance

Standard Ignition controls manufacturing from component selection through finished product assembly. The sensor design uses tight tolerance thermistor response values, and each unit is factory tested to support consistent performance out of the box.