Pinpoint Test DX: Engine Coolant Temperature (ECT) Sensor: Introduction

NOTE: Engine coolant temperature must be greater than 10°C (50°F) to pass the KOEO self-test and greater than 82°C (180°F) to pass the KOER self-test.

This pinpoint test is intended to diagnose the following:

ECT sensor (12A648)
harness circuits: ECT and SIGRTN
powertrain control module (PCM) (12A650)

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

Courtesy of FORD MOTOR CO.

TEMPERATURE SENSOR VOLTAGE AND RESISTANCE SPECIFICATIONS

Temperature		Temperature Sensor Values
°C	°F	Resistance (K ohms)
120	248	1.18
110	230	1.55
100	212	2.07
90	194	2.80
80	176	3.84
70	158	5.37
60	140	7.70
50	122	10.97
40	104	16.15
30	86	24.27
20	68	37.30
10	50	58.75
0	32	95.85
-10	14	160.31

Fig 1: Engine Coolant Temperature (ECT) Sensor Connector

Courtesy of FORD MOTOR CO.

Harness Side

Circuit	Pin
ECT (Engine Coolant Temperature)	1
SIGRTN (Signal Return)	2

Fig 2: Powertrain Control Module (PCM) Connector - For PCM Connector Views

Courtesy of FORD MOTOR CO.

Harness Side

Circuit	Pin
ECT (Engine Coolant Temperature)	E38
SIGRTN (Signal Return)	E13