Clearing Diagnostic Trouble Codes

After performing repairs, clear ECM memory of all stored Diagnostic Trouble Codes (DTCs) and freeze-frame data. DTCs and freeze-frame data may be cleared by using scan tester and scan tester manufacturer's instructions.
NOTE: If using Toyota scan tester, DTCs and freeze-frame data may be cleared by switching from CHECK mode to NORMAL mode or from NORMAL mode to CHECK mode.
DTCs and freeze-frame data may also be cleared by removing EFI fuse from fuse block, located in engine compartment. DTCs and freeze-frame data may also be cleared by disconnecting negative battery cable. However, other memory functions (clock, radio, alarm, seats, etc.) will be cancelled and must be reset.

NOTE: Not all codes listed in the following table are used on every vehicle.

TROUBLE CODE IDENTIFICATION

Code ⁽¹⁾

Component/System

Most Likely Cause

G, NE Signal Circuit (No. 1)

Open/Short Circuit, CMP Sensor, CKP Sensor, Starter Or ECM

G, NE Signal Circuit (No. 2)

Open/Short Circuit, CMP Sensor, CKP Sensor, Engine Mechanical Fault Or ECM

Ignition Signal Circuit

Open/Short Circuit, Ignitor Or ECM

A/T Control Circuit

ECM

21 ⁽²⁾

Main Heated Oxygen Sensor Circuit

Open/Short Circuit, Main Heated Oxygen Sensor Or ECM

Engine Coolant Temperature (ECT) Sensor Circuit

Open/Short Circuit, ECT Sensor Or ECM

Intake Air Temperature (IAT) Sensor Circuit

Open/Short Circuit, IAT Sensor Or ECM

Air-Fuel Ratio Lean Malfunction

Open/Short Circuit, Heated Oxygen Sensor, Ignition System, Fuel Pressure, Engine Mechanical Fault Or ECM

26 ⁽²⁾

Air-Fuel Ratio Rich Malfunction

Open/Short Circuit, Heated Oxygen Sensor, Ignition System, Fuel Pressure, Engine Mechanical Fault Or ECM

27 ⁽²⁾

Sub-Heated Oxygen Sensor Circuit

Open/Short Circuit, Sub-Heated Oxygen Sensor Or ECM

Mass Airflow (MAF) Sensor Circuit

Open/Short Circuit, MAF Sensor Or ECM

Turbo Pressure Malfunction

Short Circuit, Waste Gate Valve Actuator Or ECM

Turbo Pressure Sensor Circuit Or Barometric Pressure Sensor Circuit

ECM

Throttle Position (TP) Sensor Circuit

Open/Short Circuit, TP Sensor Or ECM

No. 1 Vehicle Speed Sensor (VSS) Signal Circuit

Open/Short Circuit, VSS Or ECM

Starter Signal Circuit

Open/Short Circuit Or ECM

Sub-Throttle Position (TP) Sensor Signal

Open/Short Circuit, Sub-TP Sensor Or ECM

Switch Condition Signal Circuit

A/C Switch Circuit, TP Sensor IDL Circuit, Park/Neutral Position Switch Circuit, Accelerator Pedal & Cable Or ECM

Knock Sensor (Front) Circuit

Open/Short Circuit, Front Knock Sensor Or ECM

Knock Control CPU Malfunction

ECM

Knock Sensor (Rear) Circuit

Open/Short Circuit, Rear Knock Sensor Or ECM

71 ⁽²⁾

Exhaust Gas Recirculation (EGR) System Malfunction

Open/Short Circuit, EGR Hose Disconnected, EGR Valve Stuck, Clogged EGR Passage Or ECM

78 ⁽²⁾

Fuel Pump Control Circuit

Open/Short Circuit, Fuel Pump ECU, Fuel Pump, ECM Power Source Circuit Or ECM

⁽¹⁾	Perform appropriate circuit test.

⁽²⁾	Two-trip detection logic code. For more information, see TWO-TRIP DETECTION LOGIC under INTRODUCTION.