PINPOINT TEST DY: Engine Oil Temperature (EOT) Sensor: Introduction

WARNING: This page does not describe the selected car, but rather 31 other vehicles, including the 2008 Mercury Sable, 2008 Mercury Mountaineer, 2008 Mercury Milan, 2008 Mercury Mariner, and 2008 Mercury Grand Marquis. However, it is still accessible from the selected car via links, so may be relevant.

This pinpoint test is intended to diagnose the following:

engine oil temperature (EOT) sensor (12A648)
harness circuits: EOT and SIGRTN
powertrain control module (PCM) (12A650)

Engine oil temperature must be greater than 10°C (50°F) to pass the KOEO self-test and greater than 66°C (150°F) to pass the KOER self-test.

Voltage values calculated for VREF = 5 volts. These values can vary by 15% due to sensor and VREF variations.

Fig 1: Temperature Sensor Temperature To Voltage Graph

Courtesy of FORD MOTOR CO.

TEMPERATURE SENSOR VOLTAGE AND RESISTANCE SPECIFICATIONS

Temperature		Temperature Sensor Values
°C	°F	Voltage	Resistance (K ohms)
120	248	0.28	1.18
110	230	0.36	1.55
100	212	0.47	2.07
90	194	0.61	2.80
80	176	0.80	3.84
70	158	1.05	5.37
60	140	1.37	7.70
50	122	1.77	10.97
40	104	2.23	16.15
30	86	2.74	24.27
20	68	3.26	37.30
10	50	3.73	58.75
0	32	4.14	95.85
-10	14	4.45	160.31

Fig 2: Engine Oil Temperature (EOT) Sensor Connector - A

Courtesy of FORD MOTOR CO.

Fig 3: Engine Oil Temperature (EOT) Sensor Connector - B

Courtesy of FORD MOTOR CO.

Vehicle	Connector	Pin	Circuit
Mustang	A	2 1	SIGRTN EOT
All other vehicles	B	2 1	SIGRTN EOT

For PCM connector views or reference values, refer to the REFERENCE VALUES article.

Connector	Pin	Circuit
170 Pin	E58 B35 E57 E27	SIGRTN VPWR VREF EOT