Retrieving the trouble codes on your OBD I Toyota Corolla isn't difficult. In this tutorial, I'll explain how you can do it in a step-by-step way.
Checking to see what trouble code is lighting up the check engine light (malfunction indicator light -MIL) is done by jumpering together the TE1 and E1 terminals of the Data Link Connector (DLC) with a jumper wire (with the Key On Engine Off).
Once the jumper wire is installed, the malfunction indicator light (MIL) will start flashing the trouble codes stored in the fuel injection computer's memory.
Contents of this tutorial:
You can find this tutorial in Spanish here: Cómo Leer Los Códigos OBD I (1990-1995 1.6L Toyota Corolla) (at: autotecnico-online.com).
APPLIES TO: This tutorial applies to the following vehicles:
- 1.6L (4A-FE) Toyota Corolla: 1990, 1991, 1992, 1993, 1994, 1995.
- 1.6L (4A-GE) Toyota Corolla: 1990, 1991.
- 1.6L Geo Prizm: 1993, 1994, 1995.
Reading The ON/OFF Flashes Of The Check Engine Light
![Reading The ON/OFF Flashes Of The Check Engine Light. How To Retrieve Toyota Corolla OBD I Trouble Codes (1990, 1991, 1992, 1993, 1994, 1995 1.6L Toyota Corolla And Geo Prizm) Reading The ON/OFF Flashes Of The Check Engine Light. How To Retrieve Toyota Corolla OBD I Trouble Codes (1990, 1991, 1992, 1993, 1994, 1995 1.6L Toyota Corolla And Geo Prizm)](/images/articles-600-699/640/643/image_3.webp)
As mentioned at the beginning, your OBD I Toyota Corolla flashes the malfunction indicator light (MIL -also known as the check engine light CEL) once you have jumpered terminals TE1 and E1 in the diagnostic link connector (DLC).
The DLC is located on the left strut tower in the engine compartment. To see a photo of the DLC, go to:
These are the steps to retrieve the trouble codes:
- Make sure your battery is fully charged before starting (its customary to place a charger on the battery while retrieving trouble codes to keep the battery from discharging).
- Turn the key to the On position but don't start the vehicle.
- Jumper terminals TE1 and E1 of the diagnostic link connector in the engine compartment.
- Count the number of flashes of the malfunction indicator light (MIL).
- If no trouble codes are present:
- The MIL will flash continuously and evenly (see illustration below).
- If trouble codes are present:
- The MIL will flash the trouble codes in a specific pattern.
- The digits of the trouble code will be flashed at about 1/2 (.5) second intervals. A 1 1/2 (1.5) second pause will separate first and second digits of the code (see illustration above).
- If more than one trouble code is stored, a 2 1/2 (2.5) second pause will separate the next flashed trouble code.
- Once all trouble codes are flashed. A 4 1/2 (4.5) second pause will occur. After this 4.5 second pause, the trouble codes will be repeated.
- Trouble codes are flashed in order of smallest to largest number.
Once you've confirmed and written down the trouble codes, remove the jumper wire from the diagnostic link connector (DLC) and turn the key to the Off position.
![Reading The ON/OFF Flashes Of The Check Engine Light. How To Retrieve Toyota Corolla OBD I Trouble Codes (1990, 1991, 1992, 1993, 1994, 1995 1.6L Toyota Corolla And Geo Prizm) Reading The ON/OFF Flashes Of The Check Engine Light. How To Retrieve Toyota Corolla OBD I Trouble Codes (1990, 1991, 1992, 1993, 1994, 1995 1.6L Toyota Corolla And Geo Prizm).](/images/articles-600-699/640/643/image_4.webp)
Location Of The Diagnostic Link Connector (DLC)
![Location Of The Diagnostic Link Connector (DLC). How To Retrieve Toyota Corolla OBD I Trouble Codes (1990, 1991, 1992, 1993, 1994, 1995 1.6L Toyota Corolla And Geo Prizm) Location Of The Diagnostic Link Connector (DLC). How To Retrieve Toyota Corolla OBD I Trouble Codes (1990, 1991, 1992, 1993, 1994, 1995 1.6L Toyota Corolla And Geo Prizm)](/images/articles-600-699/640/643/image_5.webp)
The diagnostic link connector (DLC) on your Toyota Corolla is located in the engine compartment. More specifically, it's attached to the left-side strut tower (see image above).
Toyota OBD I Diagnostic Trouble Code Definitions
1990-1995 EFI Toyota Corolla OBD I Trouble Code Definitions | |
---|---|
Code | Description |
11 | ECU Battery Power Malfunction |
12 | G and NE Signal Circuit (No. 1) -RPM Signal Problem |
13 | G and NE Signal Circuit (No. 2) -RPM Signal Problem |
14 | Ignition Signal Circuit |
21 | Oxygen Sensor Circuit |
22 | Coolant Temp Sensor Circuit |
24 | Intake Air Temp Sensor Circuit |
25 | Air/Fuel Ratio Lean Malfunction |
26 | Air/Fuel Ratio Rich Malfunction |
27 | Sub-Oxygen Sensor Circuit (California Only) |
31 | Manifold Absolute Pressure (MAP) Sensor Circuit (MAP Sensor Equipped) |
31 | Air Flow Meter Sensor Circuit (MAF Sensor Equipped) |
41 | Throttle Position Sensor (TPS) Circuit Malfunction |
42 | Vehicle Speed Sensor (VSS) Signal Circuit |
43 | Starter Signal Circuit |
51 | Switch Condition Signal Circuit |
52 | Knock Sensor Signal Malfunction |
53 | Knock Control in ECU Fault |
71 | EGR System Malfunction |
72 | Fuel Cut Solenoid Signal Malfunction |
More 1.6L Toyota Corolla Tutorials
There are several more 'how to' tutorials that I've written that are 1.6L Toyota Corolla specific, that may be of further help. You can find them here:
Here's a small sample of the tutorials you'll find in the index:
- How To Test The Throttle Position Sensor (1989-1997 1.6L Toyota Corolla).
- How To Do A Cylinder Balance Test (1989-1997 1.6L Toyota Corolla).
- TPS Idle Switch Multimeter Test (1989-1997 1.6L Toyota Corolla).
- How To Test The Fuel Pump (1989-1993 1.6L Toyota Corolla).
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