Engine Controls - Sensor Operating Range Charts: Introduction

Sensor operating range information can help determine if a sensor is out of calibration. An out-of-calibration sensor may not set a trouble code, but it may cause driveability problems.

NOTE: Unless stated otherwise in test procedure, perform all voltage tests using a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance.

COMPONENT RESISTANCE VALUES @ 68°F (20°C)

Component		Ohms
Crankshaft Position (CKP) Sensor		1235-1365
EVAP Purge Control Valve		20-40
Fuel Injector (GEMS)		15.7-16.7
Fuel Injector (BOSCH)		13.8-15.2
HO2S Heater		5.7
IAC Stepper Motor Coil		51-55
Ignition Coil (GEMS)
Primary Coil		0.8
Secondary Coil		13,000
Ignition Coil (BOSCH)
Primary Coil		0.45-0.55
Secondary Coil		12,000-14,600
Throttle Position Sensor		3200-4800

ENGINE COOLANT TEMPERATURE SENSOR OUTPUT VALUES (GEMS)

Temperature °F (°C)

⁽¹⁾ Ohms

⁽¹⁾ Output Voltage

-22 (-30)

28,000

4.70

14 (-10)

9000

4.20

68 (20)

2500

2.70

104 (40)

1050

2.00

140 (60)

600

1.20

176 (80)

330

0.75

266 (130)

0.25

⁽¹⁾	Values are approximate.

Fig 1: Engine Coolant Temperature Sensor Output Values (Bosch)

Courtesy of LAND ROVER NORTH AMERICA, INC.

ENGINE FUEL TEMPERATURE SENSOR RESISTANCE (GEMS)

Temperature °F (°C)

⁽¹⁾ Ohms

-22 (-30)

23,000-32,000

14 (-10)

8400-10,200

68 (20)

2350-2650

104 (40)

1000-1300

140 (60)

520-670

176 (80)

290-365

⁽¹⁾	Resistance values are approximate.

FUEL TANK SENDING UNIT RESISTANCE (BOSCH)

Fuel Gauge Reading

Approximate Fuel Tank Volume Gals. (L)

Sender Unit Resistance Ohms

FULL

25 (95)

⁽¹⁾ 15-19

3/4

18.8 (71)

1/2

12.7 (48)

1/4

6.4 (24)

110

RESERVE (Fuel Light ON)

2.9 (11)

⁽²⁾ 146-158

EMPTY

Zero (0)

⁽³⁾ 245-270

⁽¹⁾	When the fuel gauge registers FULL the sender unit resistance should be approximately 15-19 ohms and the output voltage should be approximately one volt.

⁽²⁾	Low fuel indicator light will illuminate when the sender unit resistance is more than 175 ohms and the output voltage is approximately 2.77 volts. Low fuel indicator light will go out when sender unit resistance is less than 117 ohms and the output voltage is approximately 2.40 volts.

⁽³⁾	When the fuel gauge resisters EMPTY the sender unit resistance should be approximately 245-270 ohms and the output voltage should approximately 3.16 volts.

HEATED OXYGEN SENSOR (HO2S) OUTPUT VOLTAGE (GEMS)

Condition

⁽¹⁾ Volts

Primary HO2S

Lean

4.7

Rich

0.2

Secondary HO2S

Lean

0.9

Rich

0.1

⁽¹⁾	Voltage should pulse between values. Voltage values are approximate.

HEATED OXYGEN SENSOR (HO2S) OUTPUT VOLTAGE (BOSCH)

Condition

Volts

Primary HO2S

⁽¹⁾ 100-900 mV

Secondary HO2S

⁽²⁾ 200-650 mV

⁽¹⁾	Voltage should switch from high to low and back at approximately 0.5 Hz.

⁽²⁾	Voltage should be static or change high to low and back slowly.

HEATED OXYGEN SENSOR (HO2S) HEATER RESISTANCE (GEMS)

Measured Between Terminals No.

⁽¹⁾ Ohms

3 & 4

5.7

⁽¹⁾	At 68°F (20°C).

INTAKE AIR TEMPERATURE (IAT) SENSOR RESISTANCE (GEMS)

Temperature °F (°C)

⁽¹⁾ Ohms

-22 (-30)

23,000-32,000

14 (-10)

8400-10,200

68 (20)

2350-2650

104 (40)

1000-1300

140 (60)

520-670

176 (80)

290-365

⁽¹⁾	Resistance values are approximate.

Fig 2: Intake Air Temperature (IAT) Sensor Output Values (Bosch)

Courtesy of LAND ROVER NORTH AMERICA, INC.

MASS AIRFLOW (MAF) SENSOR OUTPUT VOLTAGE (GEMS)

Airflow	Output Voltage
Minimum	Zero
0.3 lbs/min (0.1 kg/min)	0.8
0.4 lbs/min (0.2 kg/min)	1.0
0.5 lbs/min (0.2 kg/min)	1.1
Engine @ Idle	1.4
1.2 lbs/min (0.5 kg/min)	1.6
2.1 lbs/min (1.0 kg/min)	2.0
3.7 lbs/min (1.7 kg/min)	2.4
6.0 lbs/min (2.7 kg/min)	2.8
8.6 lbs/min (3.9 kg/min)	3.1
11.9 lbs/min (5.4 kg/min)	3.5
16.5 lbs/min (7.5 kg/min)	3.9
22.5 lbs/min (10.2 kg/min)	4.3
29.1 lbs/min (13.2 kg/min)	4.7
Maximum	5.0

Fig 3: Mass Airflow (MAF) Sensor Output Voltage (Bosch)

Courtesy of LAND ROVER NORTH AMERICA, INC.

THROTTLE POSITION (TP) SENSOR VOLTAGE (GEMS)

Position	Volts
Closed Throttle	Less Than 0.5
Idle	Approximately 0.6
Wide Open Throttle (WOT)	More Than 4.5