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Trouble Code Charts

TROUBLE CODE IDENTIFICATION

Code No. System Affected Probable Cause
No Code System Normal System Normal
11 (1) ECU (B+) Ign. Switch/Circuit, ECU Main Relay/Ckt
12 & 13  RPM Signal Dist./Circuit, ECU,
14  Ignition Signal Igniter/Circuit, Ign. Coil/Ckt, ECU
21  O2 Sensor & O2 Heater Signal O2 Sensor/Ckt, (2) O2 Sensor Heater/Ckt, ECU
22  Temp. Sensor/Switch Signal Coolant Temp. Sensor/Ckt, Coolant Temp. Switch/Ckt, ECU
24  Intake Air Temp. Sensor Signal Intake Air Temp. Sensor/Ckt, ECU
25  Lean Air/Fuel Mixture Injector/Ckt, O2 Sensor/Ckt, ECU, Fuel Line Press., Air Leak, Airflow Meter, Ignition System
26  Rich Air/Fuel Mixture Injector/Ckt, O2 Sensor/Ckt, Fuel Line Press., Airflow Meter, (1) Vacuum Sensor, Cold Start Injector, ECU
27 (2) Sub-O2 Sensor Signal Sub-O2 Sensor/Circuit, ECU
31 (3) Airflow Meter/Vac. Sensor Signal Airflow Meter/Ckt, ECU, Vacuum Sensor/Circuit, Vacuum Switch/Circuit
42  Vehicle Speed Sensor Signal Vehicle Speed Sensor/Ckt, ECU
43  Starter Signal Ignition Switch/Ckt, ECU, Starter Signal Ckt
51  Switch Signal A/C Switch/Ckt, A/C Amplifier, Throttle Position Sensor/Ckt, ECU
71 (4) EGR System Malfunction EGR System (valve, hoses, temp. sensors, vacuum switching valves), ECU
72 Fuel Cut Solenoid Signal Fuel Cut Solenoid/Ckt, ECU
(1) Corolla 4A-FE only.
(2) Corolla 4A-GE only.
(3) Corolla 4A-GE use airflow meter. With 4A-FE use vacuum sensor.
(4) Not used on Corolla 4A-FE. California only.
TROUBLE CODE DIAGNOSTIC HINTS (FUEL INJECTED VEHICLES)

Trouble Code Diagnostic Hints
11 Momentary Interruption Of Power Supply To ECU Could Also Indicate Loss Of ECU E1 Ground Connection
12 No "Ne" (RPM) Ignition Signal To ECU Within 2 Seconds After Engine Is Cranked No "G" Ignition Signal To ECU 2 Times In A Row When Engine Speed Is Between 500-4000 RPM
13 No "Ne" (RPM) Ignition Signal To ECU When Engine Speed Is Above 1500 RPM Signal Is Generated By Pick-Up Coils In Distributor
14 No "IGF" Ignition Signal To ECU From Ignitor Several Times In Succession
21 (1) Detects Deterioration Of Oxygen Sensor Open Or Short In Oxygen Sensor Circuit
22 Open Or Short In Coolant Temp. Sensor/Switch Signal
24 Open Or Short Circuit In Intake Air Temp. Sensor Signal
25 Open Circuit In O2 Sensor Signal Signal Sent By O2 Sensor For Several Seconds During Air/Fuel Ratio Feedback Correction
26 Rich Signal Sent By O2 Sensor For Several Seconds During Air/Fuel Ratio Feedback Correction
27 Open Or Short In Sub-O2 Sensor Signal
31 (4A-FE Only) Open Or Short In Vacuum Sensor/Switch Signal
31 & 32 Short Circuit Between Terminals Of Airflow Meter
34 Turbocharger Pressure Is Abnormal Code May Also Set If Airflow Meter Is Faulty
35 Open Circuit In High Altitude Compensator Signal
41 Open Or Short In Throttle Position Sensor Signal "IDL" & "PSW" Signals Are Output At Same Time For Several Seconds
42 No "SPD" Signal From Vehicle Speed Sensor For 8 Seconds With Engine Speed Between 2300-5500 RPM & Coolant Temp. Is Below 176°F (80°C) Except When Racing The Engine
43 No "STA" Signal To ECU Until Engine Reaches 800 RPM With Vehicle Not Moving
51 Problem In One Of 3 Switches ECU Monitors, Throttle Position Sensor ("IDL" Signal) Neutral Safety Switch ("NSW" Signal On A/T) A/C Signal To ECU Occurs When TPS Is At Idle & A/C Switch Is "ON" And Check Connector "E1" And "TE1" Is Jumpered
52 Open Or Short Circuit In Knock Sensor Signal
53 Knock Control In ECU Is Faulty
71 EGR Valve Normally Closed, Or Clogged Hose Open Circuit In EGR Temperature Sensor Signal EGR Gas Below Predetermined Level During EGR Control
72 Open Circuit In Fuel-Cut Solenoid Signal
(1) Also detects faults in O2 sensor heater, if equipped.