Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

2003 Mitsubishi Montero XLSFACTORY OEM SERVICE PROCEDURE

Diagnostic Trouble Code Definitions

DIAGNOSTIC TROUBLE CODE DEFINITIONS

DTC ⁽¹⁾

Definition

Volume Airflow Circuit Range/Performance Problem

Volume Airflow Circuit Low Input

P0106 ⁽⁴⁾

Barometric Pressure Circuit Range/Performance Problem

Barometric Pressure Circuit Low Input

Barometric Pressure Circuit High Input

Intake Air Temperature Circuit Range/Performance Problem

Intake Air Temperature Circuit Low Input

Intake Air Temperature Circuit High Input

Engine Coolant Temperature Circuit Range/Performance Problem

Engine Coolant Temperature Circuit Low Input

Engine Coolant Temperature Circuit High Input

Throttle Position Sensor (Main) Circuit Low Input

Throttle Position Sensor (Main) Circuit High Input

Insufficient Coolant Temperature For Closed Loop Fuel Control

Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)

Heated Oxygen Sensor Circuit (Bank 1 Sensor 1)

Heated Oxygen Sensor Circuit Low Voltage (Bank 1 Sensor 1)

Heated Oxygen Sensor Circuit High Voltage (Bank 1 Sensor 1)

Heated Oxygen Sensor Circuit Slow Response (Bank 1 Sensor 1)

P0134 ⁽⁴⁾

Heated Oxygen Sensor Circuit No Activity Detected (Bank 1 Sensor 1)

Heated Oxygen Sensor Heater Circuit (Bank 1 Sensor 1)

Heated Oxygen Sensor Circuit (Bank 1 Sensor 2)

Heated Oxygen Sensor Circuit Low Voltage (Bank 1 Sensor 2)

Heated Oxygen Sensor Circuit High Voltage (Bank 1 Sensor 2)

Heated Oxygen Sensor Circuit Slow Response (Bank 1 Sensor 2)

Heated Oxygen Sensor Heater Circuit (Bank 1 Sensor 2)

Heated Oxygen Sensor Circuit (Bank 2 Sensor 1)

Heated Oxygen Sensor Circuit Low Voltage (Bank 2 Sensor 1)

Heated Oxygen Sensor Circuit High Voltage (Bank 2 Sensor 1)

Heated Oxygen Sensor Circuit Slow Response (Bank 2 Sensor 1)

P0154 ⁽⁴⁾

Heated Oxygen Sensor Circuit No Activity Detected (Bank 2 Sensor 1)

Heated Oxygen Sensor Heater Circuit (Bank 2 Sensor 1)

Heated Oxygen Sensor Circuit (Bank 2 Sensor 2)

Heated Oxygen Sensor Circuit Low Voltage (Bank 2 Sensor 2)

Heated Oxygen Sensor Circuit High Voltage (Bank 2 Sensor 2)

Heated Oxygen Sensor Circuit Slow Response (Bank 2 Sensor 2)

Heated Oxygen Sensor Heater Circuit (Bank 2 Sensor 2)

System Too Lean (Bank 1)

System Too Rich (Bank 1)

System Too Lean (Bank 2)

System Too Rich (Bank 2)

Fuel Tank Temperature Sensor Circuit Range/Performance

Fuel Tank Temperature Sensor Circuit Low Input

Fuel Tank Temperature Sensor Circuit High Input

Injector Circuit-Cylinder 1

Injector Circuit-Cylinder 2

Injector Circuit-Cylinder 3

Injector Circuit-Cylinder 4

Injector Circuit-Cylinder 5

Injector Circuit-Cylinder 6

Throttle Position Sensor (Sub) Circuit Low Input

Throttle Position Sensor (Sub) Circuit High Input

Random/Multiple Cylinder Misfire Detected

Cylinder 1 Misfire Detected

Cylinder 2 Misfire Detected

Cylinder 3 Misfire Detected

Cylinder 4 Misfire Detected

Cylinder 5 Misfire Detected

Cylinder 6 Misfire Detected

Knock Sensor Circuit

Crankshaft Position Sensor Circuit

Camshaft Position Sensor Circuit

Exhaust Gas Recirculation Flow Insufficient Detected

Exhaust Gas Recirculation Control Circuit

Warm Up Catalyst Efficiency Below Threshold (Bank 1)

Warm Up Catalyst Efficiency Below Threshold (Bank 2)

Evaporative Emission System Incorrect Purge Flow

Evaporative Emission System Leak Detected (Small Leak)

Evaporative Emission System Purge Control Valve Circuit

Evaporative Emission System Vent Control

Evaporative Emission System Pressure Sensor Range/Performance

Evaporative Emission System Pressure Sensor Low Input

Evaporative Emission System Pressure Sensor High Input

Evaporative Emission System Leak Detected (Gross Leak)

Evaporative Emission System Leak Detected (Very Small Leak)

Fuel Level Sensor Circuit Range/Performance

P0500 ⁽³⁾

Vehicle Speed Sensor Malfunction

Immobilizer Malfunction

Power Steering Pressure Sensor Circuit Range/Performance

Power Steering Pressure Sensor Circuit Intermittent

Powertrain Control Module Main Processor Malfunction

Throttle Actuator Control Motor Circuit Range/Performance Problem

Throttle Position Sensor Power Supply

Throttle Actuator Control Motor Relay Circuit Malfunction

Intake Manifold Tuning Circuit Malfunction

P0705 ⁽³⁾

Transmission Range Switch Circuit Malfunction (RPNDL Input)

P0712 ⁽³⁾

Transmission Fluid Temperature Sensor Circuit Low Input

P0713 ⁽³⁾

Transmission Fluid Temperature Sensor Circuit High Input

P0715 ⁽³⁾

Input/Turbine Speed Sensor Circuit

P0720 ⁽³⁾

Output Speed Sensor Circuit

P0731 ⁽³⁾

Gear 1 Incorrect Ratio

P0732 ⁽³⁾

Gear 2 Incorrect Ratio

P0733 ⁽³⁾

Gear 3 Incorrect Ratio

P0734 ⁽³⁾

Gear 4 Incorrect Ratio

P0735 ⁽³⁾

Gear 5 Incorrect Ratio

P0736 ⁽³⁾

Gear R Incorrect Ratio

P0741 ⁽³⁾

Torque Converter Clutch Circuit Performance Or Stuck Off

P0742 ⁽³⁾

Torque Converter Clutch Circuit Stuck On

P0743 ⁽³⁾

Torque Converter Clutch Circuit Electrical

P0753 ⁽²⁾⁽³⁾

Shift Solenoid "A" Electrical

P0758 ⁽²⁾⁽³⁾

Shift Solenoid "B" Electrical

P0763 ⁽²⁾⁽³⁾

Shift Solenoid "C" Electrical

P0768 ⁽²⁾⁽³⁾

Shift Solenoid "C" Electrical

P0773 ⁽²⁾⁽³⁾

Shift Solenoid "E" Electrical

Manifold Differential Pressure Sensor Circuit Malfunction

Communication Malfunction (Between PCM & Throttle Actuator Control Module)

P1603 ⁽⁴⁾

Battery Backup Circuit Malfunction

P1751 ⁽³⁾

A/T Control Relay Malfunction

Throttle Actuator Control Motor Circuit (Open)

Throttle Actuator Control Motor Magneto Malfunction

Throttle Actuator Control Motor Circuit (Shorted Low)

Throttle Actuator Control Motor Circuit (Shorted High)

Throttle Actuator Control Processor Malfunction

Accelerator Pedal Position Sensor (Main) Circuit Range/Performance Problem

Accelerator Pedal Position Sensor (Main) Circuit Low Input

Accelerator Pedal Position Sensor (Main) Circuit High Input

Accelerator Pedal Position Sensor (Sub) Circuit Range/Performance Problem

Accelerator Pedal Position Sensor (Sub) Circuit Low Input

Accelerator Pedal Position Sensor (Sub) Circuit High Input

Throttle Position Sensor (Main & Sub) Range/Performance Problem

Accelerator Pedal Position Sensor (Main & Sub) Range/Performance Problem

⁽¹⁾	All DTCs use two-trip fault detection logic unless otherwise specified. If DTC is for a fault that may affect emissions, MIL will also illuminate.

⁽²⁾	This DTC will set on first trip fault is detected.

⁽³⁾	For diagnostic procedures, see appropriate DIAGNOSTICS article in AUTOMATIC TRANSMISSIONS.

⁽⁴⁾	The MIL illuminates only on the first detection of the malfunction.

Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.

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