Engine Controls - Sensor Operating Range Charts: Introduction

Sensor operating range information can help determine if a sensor is out of calibration. An out-of-calibration sensor may not set a trouble code, but it may cause driveability problems.

NOTE: Unless stated otherwise in test procedure, perform all voltage tests using a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance.

ENGINE COOLANT TEMPERATURE (ECT) SENSOR RESISTANCE

Temperature - °F (°C)	Ohms
0 (-18)	14,650
19 (-7)	8100
39 (4)	4780
70 (21)	2350
100 (38)	1250
160 (71)	400
210 (99)	190

INTAKE AIR TEMPERATURE (IAT) SENSOR RESISTANCE

Temperature - °F (°C)	Ohms
0 (-18)	14,650
19 (-7)	8100
39 (4)	4780
70 (21)	2350
100 (38)	1250
160 (71)	400
210 (99)	190

Manifold Absolute Pressure (MAP) Sensor

For information on MAP sensor, see ENGINE SENSORS & SWITCHES in I - SYS/COMP TESTS article in the ENGINE PERFORMANCE Section.

OXYGEN SENSOR HEATER RESISTANCE

Application

Ohms

Upgraded Emissions

⁽¹⁾

⁽¹⁾	A low resistance should be present.

THROTTLE POSITION (TP) SENSOR RESISTANCE

Application

Ohms

Standard Emissions

Between Terminals 1 & 2 ⁽¹⁾

0-5000

Between Terminals 1 & 2 ⁽²⁾

Infinity

Between Terminals 1 & 2 ⁽³⁾

0-5000

Between Terminals 1 & 3 ⁽³⁾

240-1140

Between Terminals 1 & 3 ⁽⁴⁾

3170-6600

Between Terminals 1 & 4

4370-8130

Upgraded Emissions

⁽⁵⁾

⁽¹⁾	With .012" (.30 mm) feeler gauge installed between throttle stop screw and lever.

⁽²⁾	With .035" (.89 mm) feeler gauge installed between throttle stop screw and lever.

⁽³⁾	Throttle valve at idle position.

⁽⁴⁾	Throttle valve at fully open position.

⁽⁵⁾	For information on TP sensor, see THROTTLE POSITION (TP) SENSOR in ADJUSTMENTS ARTICLE.

Vehicle Speed Sensor

For information on vehicle speed sensor, see ENGINE SENSORS & SWITCHES in I - SYS/COMP TESTS article in the ENGINE PERFORMANCE Section.

Fig 1: Identifying TP Sensor Terminals (Standard Emissions)

Courtesy of GENERAL MOTORS CORP.