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 (DISCOVERY SERIES II & RANGE ROVER)

Component		Ohms @ 68°F (20°C)
Crankshaft Position (CKP) Sensor		1235-1365
EVAP Purge Control Valve		20-40
Fuel Injector (Bosch)		13.8-15.2
HO2S Heater		5.7
IAC Stepper Motor Coil		51-55
Ignition Coil (Bosch)
Primary Coil		0.45-0.55
Secondary Coil		12,000-14,600
Throttle Position Sensor		3200-4800

Fig 1: Engine Coolant Temperature Sensor Output Values (Discovery Series II & Range Rover)

Courtesy of LAND ROVER NORTH AMERICA, INC.

FUEL INJECTOR RESISTANCE

Application	Ohms @ 68°F (20°C)
Discovery Series II & Range Rover	13.8-15.2
Freelander	13-16

FUEL TANK SENDING UNIT RESISTANCE (DISCOVERY SERIES II & RANGE ROVER)

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.

FUEL TANK SENDING UNIT RESISTANCE (FREELANDER)

Fuel Gauge Reading	Sender Unit Resistance Ohms
FULL	135
1/2	302
RESERVE (Fuel Light ON)	413
EMPTY	503

HEATED OXYGEN SENSOR (HO2S) OUTPUT VOLTAGE (DISCOVERY SERIES II & RANGE ROVER)

Component

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.

HO2S HEATER ELEMENT RESISTANCE (FREELANDER)

Component	Ohms @ 68°F (20°C)
Primary & Secondary HO2S	6

THROTTLE POSITION SENSOR VOLTAGE (DISCOVERY SERIES II & RANGE ROVER)

TP Sensor Position	Volts
Minimum	Zero
Idle	0.3-0.5
Wide Open Throttle (WOT)	4.5
Maximum	5.0

THROTTLE POSITION SENSOR VOLTAGE SPECIFICATIONS (FREELANDER)

Application

Voltage

TP Sensor 1

Closed Throttle

Approx. 0.5

Wide Open Throttle (WOT)

Approx. 4.5

TP Sensor 2 ⁽¹⁾

Closed Throttle

Approx. 4.5

Wide Open Throttle (WOT)

Approx. 0.5

⁽¹⁾	TP sensor 2 is used as a plausability check for TP sensor 1.

Fig 2: Intake Air Temperature (IAT) Sensor Output Values (Discovery Series II & Range Rover)

Courtesy of LAND ROVER NORTH AMERICA, INC.

Fig 3: Mass Airflow (MAF) Sensor Output Voltage (Discovery Series II & Range Rover)

Courtesy of LAND ROVER NORTH AMERICA, INC.