Pinpoint Tests DL: Cylinder Head Temperature (CHT) Sensor: Introduction

This pinpoint test is intended to diagnose the following:

• cylinder head temperature (CHT) sensor (6G004)
• cylinder head temperature 2 (CHT2) sensor (6G004)
• harness circuits: CHT, CHT2, and SIGRTN
• PCM (12A650)

On applications that do not use an engine coolant temperature (ECT) sensor, the CHT sensor is used to determine the engine coolant temperature. To cover the entire temperature range of both the CHT and ECT sensors, the PCM has a dual switching resistor circuit on the CHT input. A graph showing the temperature switching from the COLD END line to the HOT END line, with increasing temperature and back with decreasing temperature is included. Note the temperature to voltage overlap zone. Within this zone it is possible to have either a COLD END or HOT END value at the same temperature. For example, at 90°C (194°F) the voltage could read either 0.60 volt or 3.71 volts. Refer to the table for the expected values.

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

Courtesy of FORD MOTOR CO.

Cylinder Head Temperature (CHT) And CHT2 Sensor Expected Values 

Temperature		CHT Sensor Values
°C	°F	Cold End (volts)	Hot End (volts)	Resistance (K ohms)
-40	-40	4.89	-	965.808
-30	-22	4.81	-	513.019
-20	-4	4.67	-	283.664
-10	14	4.45	-	162.584
0	32	4.14	-	96.255
10	50	3.73	-	59.175
20	68	3.26	-	37.387
30	86	2.74	-	24.215
40	104	2.23	-	16.043
50	122	1.76	-	10.85
60	140	1.36	-	7.487
70	158	1.04	-	5.268
80	176	0.79	3.99	3.775
85	185	0.69	3.86	3.215
90	194	0.60	3.71	2.75
95	203	0.53	3.56	2.361
100	212	0.46	3.41	2.034
110	230	-	3.07	1.523
120	248	-	2.74	1.155
130	266	-	2.41	0.8866
140	284	-	2.10	0.6891
150	302	-	1.81	0.5417
160	320	-	1.55	0.4301
170	338	-	1.33	0.3449
180	356	-	1.13	0.2791
190	374	-	0.96	0.2278
200	392	-	0.82	0.1875
210	410	-	0.70	0.155
220	428	-	0.60	0.130
230	446	-	0.51	0.109
240	464	-	0.44	0.092
250	482		0.35	0.078
260	500		0.33	0.067

Vehicle	Connector	Pin	Circuit
E-Series, F-150 5.0L, F-150 3.5L, F-650/F-750, Motorhome/Stripped Chassis/Step Van	A	2 1	SIGRTN CHT
All other vehicles	B	2 1	SIGRTN CHT

Vehicle	Connector		Circuit
Aviator, EcoSport 1.0L, Edge, Explorer 3.0L, Explorer 3.3L, Mustang 2.3L, Nautilus, Ranger, Transit Connect	A	2 1	SIGRTN CHT2
Bronco Sport, Corsair, EcoSport 1.5L, Escape/Kuga, Explorer 2.3L, F-150 2.7L	B	2 1	SIGRTN CHT2
EcoSport 2.0L	C	2 1	SIGRTN CHT2

Powertrain Control Module (PCM) Connector 

For PCM connector views or reference values, refer to Typical Diagnostic Reference Values.

Vehicle	Connector	Pin	Circuit
Aviator, Explorer 3.0L, Explorer 3.3L	306 PIN	E99 E8	SIGRTN CHT2
Continental, EcoSport 1.0L Automatic Transmission, EcoSport 2.0L	198 PIN	E20 E36	SIGRTN CHT2
Corsair 2.5L, Escape/Kuga 2.5L	198 PIN	E39 E40	CHT SIGRTN
E-Series, Expedition Base, F-650/F-750, F-Series Super Duty 7.3L, Motorhome/Stripped Chassis/Step Van, Mustang 5.0L, Navigator Base, Transit TiVCT 3.5L	306 PIN	E8 E99	CHT SIGRTN
EcoSport 1.0L Manual Transmission	198 PIN	E10 E36	SIGRTN CHT2
EcoSport 1.5L Automatic Transmission, KA 1.5L Automatic Transmission	198 PIN	E35 E39	SIGRTN CHT2
EcoSport 1.5L Manual Transmission, KA 1.2L, KA 1.5L Manual Transmission	112 PIN	E5 E21	SIGRTN CHT2
Edge 2.7L, Nautilus 2.7L	306 PIN	E20 E8	SIGRTN CHT2
Expedition High Output, Navigator High Output	198 PIN	E36 E10	CHT SIGRTN
F-150 2.7L	306 PIN	E39 E70	SIGRTN CHT2
F-150 3.3L, F-150 3.5L, F-150 5.0L	306 PIN	E70 E39	CHT SIGRTN
F-Series Super Duty 6.2L, Mustang 5.2L Supercharged	306 PIN	E8 E49	CHT SIGRTN
Ford GT	198 PIN	E36 E56	CHT SIGRTN
Mustang TiVCT 5.2L	198 PIN	E47 E49	CHT SIGRTN
Transit GTDI 3.5L	306 PIN	E8 E20	CHT SIGRTN
Transit Connect 2.0L	198 PIN	E40 E13 E36	CHT SIGRTN CHT2
Transit Connect 2.5L	198 PIN	E39 B35	CHT SIGRTN
All other vehicles	198 PIN	E13 E40	SIGRTN CHT2