Check Engine Light On My 93 - Corolland: the Toyota Corolla Forums

Out of nowhere I was driving down the highway in my 93 with the a/c on and the check engine light comes on. Owned the car 5 years and have not seen that one before. I am closing in on 300000 miles and was just at the u-pull junkyard today getting a caliper and brake shoes for the right side. Why couldn't it have happened before I got the parts. They are $4.20 at the junkyard. The caliper and shoes were $21- a $2.50 core

The car has had a slight exhaust leak for the last couple years between the cat and the front pipe so I am thinking either the 02 sensor had a bad day or one of them took a dump.What else could it be.

The car is running fine except i noticed a possible slight roughness idling at a light this morning . Other than that everything seems normal. Should i just reset it and hope for the best or figure out how to read the codes on it and change whatever sensor , which I bet is the rear. The same one on my 95 that my daughter destroyed when she knocked off the exhaust. The one that is a bear to get too. Time to get the mapp gas out I bet.

How do i read the codes on an obd1 anyhow?

Try this site: http://www.troublecodes.net/Toyota/

[Directions are just cut from the site and listed below]

Basically jumpering two pins to enable diagnostic mode - TE1 and E1. Toyota makes a special tool to short the pins (looks like a key) or you could just use a paperclip or some solid core jumper wire. Or you could pickup an OBD-I reader for around $30-$40.

- Turn ignition switch to ON position.

- Do not start the engine.

- Place a jumper wire across TEl and El terminals in engine check connector.

- Count number of flashes from CHECK ENGINE light.

NOTE: If system is operating normally (with no detected faults), the CHECK ENGINE light will blink continuously and evenly about 2 times a second. Otherwise, the light will blink a number of times equal to the trouble code as follows:

- The light blinks only (.5 second ON, .5 second OFF) when indicating a number.

- The light will be OFF for 1.5 seconds between the first digit and the second digit of the code.

- If more than one code is stored, the light will be OFF for 2.5 seconds before the next code is displayed.

- Once all code(s) have been displayed, the light will be OFF for 4.5 seconds and then the whole sequence will repeat.

- The diagnostic code series will continue to repeat as long as the check connecter terminals TEl and El are connected.

When finished, remove the jumper wire. Clear the codes from the ECU memory (remove negative battery terminal for a minute or so).

Limited number of codes - so it can be a blessing or curse, depending on what is wrong.

OBD1 Codes

1 Normal Condition

2 Air Flow Meter signal

3 Ignition signal

4 Engine Coolant Temperature Sensor signal

5 Oxygen Sensor

6 RPM signal (Crank Angle Pulse)

7 Throttle Position Sensor signal

8 Intake Air Temperature Sensor signal

9 Vehicle Speed Sensor signal

10 Starter signal

11 Switch signal

11 ECU/ECM

12 Knock Control Sensor signal

12 RPM signal

13 Knock Control CPU (ECM)

13 RPM signal

14 Turbocharger Pressure

14 Ignition signal

21 Oxygen Sensor

22 Engine Coolant Temperature Sensor signal

23 Intake Air Temperature Sensor signal

24 Intake Air Temperature Sensor signal

25 Air-Fuel Ratio Lean

26 Air-Fuel Ratio Rich

27 Sub Oxygen Sensor signal

28 No. 2 Oxygen Sensor signal

31 Air Flow Meter signal (Vacuum Sensor signal)

32 Air Flow Meter signal

34 Turbocharger Pressure signal

35 Turbocharger Pressure Sensor signal

35 HAC Sensor signal

41 Throttle Position Sensor signal

42 Vehicle Speed Sensor signal

43 Starter signal

51 Switch signal

52 Knock Sensor signal

53 Knock Sensor signal

54 Inter-cooler ECM signal

71 EGR System

72 Fuel Cut Solenoid signal

78 Fuel Pump Control signal

81 TCM Communication

83 TCM Communication

84 TCM Communication

85 TCM Communication

Thanks fish , it showed a code 21 , just happens to be the 02 sensor . Imagine that. Now how do I know if it is the front or back one without replacing both.

I'd double check the exhaust system, but I believe that the 1993 models only have the one O2 sensor (pre-cat), no downstream sensor. That only showed up on some Cali-spec Corollas/Prisms and after 1995-1996 with the push for OBD-II systems.

I'd double check the exhaust system, but I believe that the 1993 models only have the one O2 sensor (pre-cat), no downstream sensor. That only showed up on some Cali-spec Corollas/Prisms and after 1995-1996 with the push for OBD-II systems.

right again . there is only one. The 95 has 2. I am wondering how hard that little sucker is going to take out. I sprayed it with pb blaster . I will do that again in the A.M..

I also cleaned the throttle body and put Lucas ucl in the tank . The car is running better that it has , but it was cool and rainy today. It was running fine but it had more pep through 2nd gear today.

I have to change the right side caliper and pads anyway so if I get a little grubby . so what. I do have my (GASP)

Suzuki Aerio to run to the zone for a loaner socket if I need it. I might reset the code ,which I tried today and it would not reset (pulled efi fuse), by disconnecting the battery and flaming the sensor with a torch. Sometimes it cleans them up.

My engine and throttle body were so clean , I doubt that the 02 sensor is just dirty. Ya never know. The amount of oil I burn could have finally clogged the tip. I'll let you know.

I changed the bad caliper with my $20 u-pull caliper and pad set. I know , never use old pads. Hey , they work fine. I bled the brake with wagner synthetic fluid . Brakes quit squeeking and stop fine.

I reset the code by disconnecting the battery.

I have driven 100+ miles and it has not come back on yet , but I will get a 02 sensor the next time I am near the u-pull. They are $5.

Car is running great.

298500 miles and counting. Just trying to get the old guy to 300000 . Put another quart of 10w30 in today. I am still getting 1000 miles a quart. The motor is original. Probably the best car I ever owned.5 years+ 90000 miles driven and under $2000 total with all parts and repairs. Car is still worth a grand.

My kids 95 is close.