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.

Fig 1: ECT Sensor 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: Identifying Engine Coolant Temperature (ECT) Sensor Connector

Courtesy of FORD MOTOR CO.

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

Powertrain Control Module (PCM) Connector

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

Vehicle	Connector	Pin	Circuit
EcoSport 2.0L Manual Transmission, EcoSport 1.6L	80 PIN	E25 E23	SIGRTN ECT
EcoSport 2.0L Automatic Transmission	128 PIN	E46 E34	SIGRTN ECT
Edge 2.0L, Explorer, MKT, MKX 2.0L, Taurus	198 PIN	E20 E46	SIGRTN ECT
Edge 2.7L, F-150, MKX 2.7L	198 PIN	E20 E37	SIGRTN ECT
Fiesta GTDI 1.6L, Fiesta 1.0L, Focus 1.0L	198 PIN	E10 E23	SIGRTN ECT
Fiesta TiVCT 1.6L	128 PIN	E3 E31	SIGRTN ECT
Focus GDI 2.0L	154 PIN	E33 E12	SIGRTN ECT
KA	128 PIN	E15 E27	SIGRTN ECT
All other vehicles	198 PIN	E20 E36	SIGRTN ECT