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: Engine Coolant Temperature (ECT) Sensor Voltage Graph

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 2: 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
Continental 2.7L, Continental 3.0L, Edge 2.7L, Fusion 2.7L, MKX 2.7L, MKZ 3.0L	198 PIN	E20 E37	SIGRTN ECT
EcoSport 1.0L Automatic Transmission	198 PIN	E20 E35	SIGRTN ECT
EcoSport 1.0L Manual Transmission, Fiesta 1.0L, Fiesta GTDI 1.6L	198 PIN	E10 E23	SIGRTN ECT
EcoSport 1.5L Automatic Transmission	198 PIN	E12 E33	SIGRTN ECT
EcoSport 1.5L Manual Transmission	112 PIN	E3 E23	SIGRTN ECT
Escape/Kuga 1.5L	198 PIN	E14 E59	SIGRTN ECT
F-150	306 PIN	E92 E29	SIGRTN ECT
Fiesta TiVCT 1.6L, Ranger	128 PIN	E3 E31	SIGRTN ECT
Focus 1.0L, Focus GTDI 2.0L, Focus 2.3L, Fusion 1.5L, MKZ 2.0L	198 PIN	E20 E36	SIGRTN ECT
Focus GDI 2.0L	154 PIN	E33 E12	SIGRTN ECT
KA	128 PIN	E15 E27	SIGRTN ECT
Mustang	198 PIN	E13 E38	SIGRTN ECT
All other vehicles	198 PIN	E20 E46	SIGRTN ECT