Engine Controls - Sensor Operating Range Charts - 3.5L, 3.9L & 4.2L: Introduction

NOTE: Defender service information is similar to Range Rover service information. Land Rover does not provide Defender specific service information.

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.

ENGINE COOLANT/FUEL TEMPERATURE SENSOR SPECIFICATIONS

Temperature °F (°C)	Ohms
14 (-10)	9100-9300
32 (0)	5700-5900
68 (20)	2400-2600
104 (40)	1100-1300
140 (60)	500-700
176 (80)	300-400
212 (100)	150-200

MASS AIRFLOW SENSOR SPECIFICATIONS

Application		Voltage
1987-88 Models
Ignition Switch ON		0.3-0.6
1989-Early 95 Models
Ignition Switch ON		0.2-0.7
Engine At Idle		1.4-1.8
1000 RPM		1.9
2000 RPM		2.1
3000 RPM		2.5
4000 RPM		3.0

OXYGEN SENSOR SPECIFICATIONS

Condition

⁽¹⁾ Volts

Lean

0.5

Rich

1.0

⁽¹⁾	Voltage should pulse between values.

OXYGEN SENSOR HEATER SPECIFICATIONS

Application

⁽¹⁾ Ohms

1987-88

2.7-3.4

1889-Early 95

2.5-6.0

⁽¹⁾	Resistance is measured between main relay (fuel pump relay) and ground. The value includes the resistance of the entire oxygen sensor heater circuit.

THROTTLE POSITION SENSOR SPECIFICATIONS

Application

⁽¹⁾ Specification

1987-88

Throttle Closed

0.29-0.36 Volts, 5000 Ohms Of Resistance

Throttle Open

4.6-5.0 Volts

1989-Early 95

Throttle Closed

0.09-0.55 Volts, 4000-6000 Ohms Of Resistance

Throttle Open

4.2-4.9 Volts

⁽¹⁾	Ensure a smooth switch between closed and open throttle positions.

VEHICLE SPEED SENSOR SPECIFICATIONS

Application

⁽¹⁾ Volts

1987-Early 95

0-12

⁽¹⁾	Fluctuating 6 times per left rear wheel revolution, with right rear wheel on the ground.