Trouble Code Identification

1988 Toyota Corolla SR5, 4D WagonSECTION Trouble Code Identification
TROUBLE CODE IDENTIFICATION

Code No. Circuit Affected
No Code System Normal
12 & 13 RPM Signal
14 Ignition Signal
21 O2 Sensor or O2 Heater Signal
22 Coolant Temp. Sensor Signal
24 Intake Air Temp. Sensor Signal
25 Lean Air/Fuel Mixture
26 Rich Air/Fuel Mixture
31 Airflow Meter Signal
41 Throttle Position Sensor Signal
42 Vehicle Speed Sensor Signal
43 Starter Signal
51 Switch Signal
71 (1) EGR System Malfunction
(1) Applicable to all California models.
TROUBLE CODES & PROBABLE CAUSE

Code No. Probable Cause
12 Distributor and/or Circuit, Starter Signal, Ignitor, ECU
13 Distributor and/or Circuit, ECU
14 Ignition Coil, Ignitor and/or Circuit, ECU
21 O2 Sensor and/or O2 Heater Signal and/or Circuit, ECU
22 Coolant Temp. Sensor and/or Circuit, ECU
24 Intake Air Temp. Sensor or Circuit, ECU
25 Injector and/or Circuit, O2 Sensor and/or Circuit Airflow Meter, ECU, Fuel Line Pressure Air Intake System, Ignition System
26 Injector and/or Circuit, Fuel Line Pressure, Cold Start Injector, Airflow Meter, O2 Sensor and/or Circuit, ECU and/or Circuit, ECU
31 Airflow Meter and/or Circuit, ECU
41 Throttle Position Sensor and/or Circuit, ECU
42 Vehicle Speed Sensor and/or Circuit, ECU
43 Ignition Switch and/or Circuit Starter Signal Circuit, ECU
51 Throttle Position Sensor and/or Circuit A/C Switch Circuit, A/C Amplifier, ECU Neutral/Start Switch and/or Circuit, Accelerator Pedal and/or Cable
71 (1) EGR System, EGR Gas Temp. Sensor and/or Circuit, BVSV for EGR and/or Circuit, ECU
(1) Applicable to all California models.
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.