LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 1994 >> Corolla LE >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes >> Trouble Code Identification
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Trouble Code Identification

TROUBLE CODE IDENTIFICATION (1)

Code System Affected (2) MIL In Normal Mode (2) MIL In Test Mode Probable Cause
12  RPM Signal ON N/A Distributor, Starter Or Circuit, ECM
13  RPM Signal (1.8L) (3) (4) Distributor Or Circuit, ECM
14  Ignition Signal ON N/A Ignitor Or Circuit To ECM, ECM
16 (5) A/T Control Signal (1.8L) ON N/A ECM Or Circuit
21  Oxygen Sensor Signal ON ON Oxygen Sensor Or Circuit, ECM
22  Engine Coolant Temperature Sensor Signal ON ON Engine Coolant Temp. Sensor Or Circuit, ECM
24  Intake Air Temperature Sensor Signal ON ON Intake Air Temp. Sensor Or Circuit, ECM
25  Lean Air/Fuel Mixture ON ON Injector Or Circuit, Oxygen Sensor Or Circuit Fuel Pressure, Ignition System, Vacuum Leak, Compression Pressure, ECM
26  Rich Air/Fuel Mixture ON ON Injector Or Circuit, Oxygen Sensor Or Circuit Fuel Pressure, Ignition System, Vacuum Leak, Compression Pressure, ECM
27 (6) Sub-Oxygen Sensor Signal ON ON Sub-Oxygen Sensor Or Circuit, ECM
31  MAP Sensor Signal ON ON MAP Sensor Or Circuit, ECM
41  Throttle Position Sensor Signal ON ON Throttle Position Sensor Or Circuit, ECM
42  Vehicle Speed Sensor Signal ON OFF Vehicle Speed Sensor Or Circuit, ECM
43  Starter Signal N/A OFF Starter Signal Circuit, Starter Relay, Ignition Switch Or Circuit, ECM
51  Switch Condition Signal N/A OFF A/C Switch Circuit, Park/Neutral Switch Or Circuit, TPS Or Circuit, ECM
52  (1.8L) Knock Sensor Signal ON N/A Knock Sensor Or Circuit, ECM
71 (6) EGR System Malfunction ON ON EGR System, EGR Temp. Sensor Or Circuit, EGR-VSV, ECM
(1) The 1.6L is the 4A-FE engine and 1.8L is the 7A-FE engine.
(2) ON indicates MIL on instrument panel will be illuminated. N/A indicates item is not included in malfunction diagnosis when using this mode. OFF indicates MIL on instrument panel will not be illuminated even if malfunction is detected.
(3) The MIL will be illuminated only if no "NE" signal is sent to ECM with engine at 1500 RPM or more. The MIL will not be illuminated if no "G" signal to ECM is received while "NE" signal is input 4 times to ECM when engine speed is between 500 and 4000 RPM.
(4) The MIL will not be illuminated if no "NE" signal to ECM is received at 1500 RPM or more. The MIL will be illuminated if no "G" signal to ECM is received while "NE" signal is input 4 times to ECM when engine speed is between 600 and 4000 RPM.
(5) Applies only to models with electronic-controlled automatic transaxle.
(6) Applies to California models only.