1994 Toyota T100 BaseFACTORY OEM SERVICE PROCEDURE

Trouble Code Identification

TROUBLE CODE IDENTIFICATION

Code Number System Affected (1) Normal Mode (1) Test Mode Probable Cause
12 RPM Signal ON N/A Distributor, Starter Or Circuit, ECM
13 RPM Signal ON ON Distributor Or Circuit, ECM
14  Ignition Signal ON N/A Ignitor Or Circuit To ECM, ECM
16 (2) A/T Control Signal ON N/A ECM Or Circuit
21  Oxygen Sensor Signal ON ON Oxygen Sensor/Heater Or Circuit, ECM
22  Engine Coolant Temperature Sensor Signal ON ON Engine Coolant Temp. Sensor Or Circuit, ECM
24  Intake Air Sensor Signal ON ON Intake Air Temp. Sensor Or Circuit, ECM
25  Lean Air/Fuel Mixture ON ON Loose Ground, Injector Or Circuit, Oxygen Sensor/Heater Or Circuit, Fuel Pressure, Ignition System, Engine Coolant Temp. Sensor, Airflow Meter, ECM
26 Rich Air/Fuel Mixture ON ON Loose Ground, Injector Or Circuit, Oxygen Sensor/Heater Or Circuit, Fuel Pressure, Cold Start Injector Or Circuit, Engine Coolant Temp. Sensor, Airflow Meter, Compression Pressure, ECM
27 (3) Sub-Oxygen Sensor Signal ON ON Sub-Oxygen Sensor/ Heater Or Circuit, ECM
31  Airflow Meter ON ON Airflow Meter Or Circuit, ECM
32  Airflow Meter ON ON Airflow Meter Or Circuit, ECM
41  Throttle Position Sensor Signal ON (4) 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, Main 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 Knock Sensor Or Circuit, ECM
52  Knock Sensor Signal ON N/A Knock Sensor Or Circuit, ECM
53  Knock Control Signal ON N/A ECM
71  EGR System Malfunction ON ON EGR System, EGR Temp. Sensor Or Circuit, EGR-VSV, ECM
(1) 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.
(2) Applies only to models with electronic-controlled automatic transaxle.
(3) Applies to California models only.
(4) The MIL will be illuminated on California models only.
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Stop DIY work and contact a certified mechanic immediately if any of the following apply:

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  • • The engine overheats, stalls repeatedly, or misfires under load.
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