1990-1997 Toyota Camry ABS Light On: Common Causes and Fixes

By Core Brake Parts Tech Team — Circleville, OH warehouse

An amber ABS light on a 1990-1997 Toyota Camry means the anti-lock computer found a fault and switched the anti-lock function off. On these cars the most common trigger is a wheel speed sensor signal problem: a dirty sensor tip, a damaged connector, or a rusted or cracked tone ring. The good news is that this generation of Toyota ABS can flash its own trouble codes on the dash light with nothing more than a jumper wire, so you can find the fault before you buy a single part.

How the ABS on a 1990-1997 Camry Works

Not every Camry from these years was built with anti-lock brakes. If your instrument cluster has an ABS lamp that lights at key-on, your car has the system. It is made of four main pieces: a wheel speed sensor at each wheel, a toothed tone ring (sensor rotor) that spins past each sensor, a hydraulic actuator with solenoid valves and a pump motor, and the ABS computer (ECU) that ties it all together.

Toyota's technical training material explains that the ABS ECU runs a self-check once each time the ignition is switched on, cycling the solenoid valves and pump motor in sequence to test each electrical circuit. On some earlier models this check runs once the car passes about 4 mph with the brake light switch off. You may hear a short buzz or click from the actuator when it happens. That noise is normal and is not a fault.

When the ECU detects a problem in any of the signal circuits, it turns on the ABS warning light and stores a diagnostic trouble code in memory. The anti-lock function is disabled while the light is on, so the car stops like a vehicle without ABS. If the red BRAKE light is also on, treat that as a separate and more urgent warning about the base hydraulic system, such as low fluid in the master cylinder reservoir, and check it before driving.

Reading the ABS Codes Yourself

You do not need an ABS-capable scan tool on these cars. Toyota's ABS diagnosis course lays out the flash-code method:

1. Locate the data link connector. Toyota refers to DLC1 in the engine bay and DLC2 inside the car; on 1992-1995 2.2L Camrys the in-cabin connector sits under the driver's side of the dash above the pedals.
2. If your car uses a short pin in DLC1, remove it. Toyota's course notes that Camry and Avalon with Bosch ABS have no short pin, so on those cars you simply jumper the terminals.
3. Connect a jumper wire between terminals Tc and E1. Do not confuse Tc with TE1, which is the terminal used to read engine codes on the check engine light.
4. Turn the ignition on without starting the engine and watch the ABS light.

If no fault is stored, the light blinks steadily two times per second after a two second pause. If a code is stored, there is a four second pause, then the first digit blinks out, a one and a half second pause, then the second digit. Multiple codes are shown lowest number first with a two and a half second pause between them, and the whole sequence repeats.

What the Codes Mean

The exact list varies by model and year, so confirm it in the repair manual for your car, but Toyota's training chart for this family of ABS systems reads as follows:

Codes 31 through 34 are the ones you will see most. Industry technical coverage from Brake and Front End is blunt about it: wheel speed sensors are still the most common of all ABS failures.

Common Causes and How to Confirm Them

Wheel speed sensor signal problems

The Camry's sensors are the passive magnetic type: a permanent magnet core wrapped in copper windings that generates an AC signal as the tone ring teeth pass the tip. The signal is weak at low speed, so anything that weakens it further can set a code. Brake and Front End lists the usual culprits: resistance inside the sensor, resistance in the wiring and connectors, metallic debris from worn rotors or semi-metallic pads stuck to the magnetic tip, and too large an air gap between the sensor and the ring. Air gaps on passive sensors typically range from .016 in. to .050 in. (0.40 to 1.3 mm) depending on the application.

To check a sensor, unplug it and measure resistance across its two terminals with an ohmmeter, then compare the reading to the value in your repair manual. A working passive sensor spun at about one revolution per second should produce roughly 50 to 700 millivolts AC. An open or shorted reading means a bad sensor or harness; a good reading with a code usually points to the tip, the gap or the ring.

Damaged or rusted tone rings

A cracked, rusted or chipped tone ring produces an erratic signal even with a perfect sensor. Brake and Front End notes that even a tiny nick in the ring can be enough to disrupt the signal, and that ring runout should not exceed .006 in. Code 37 on this system points directly at a faulty rear sensor rotor.

Wiring and connectors

On a car this age, the sensor harness near each wheel has been flexing and taking road salt for decades. Loose or corroded connectors are a common cause of weak or intermittent signals. Inspect the harness along the strut and inner fender for rubbed-through insulation before replacing a sensor.

Mismatched tires

Wheel speed sensors compare every wheel against the others. A tire of a different diameter, such as a compact spare left on too long or a mismatched replacement tire, can make one wheel look like it is slipping.

Low voltage, relays and the pump

A weak battery or charging fault can set code 41. Relay and pump codes (11 through 14, 51) are less common than sensor faults but do happen; check fuses, relays and ground connections before condemning the actuator, which Toyota states cannot be disassembled for service.

Toyota's Built-In Speed Sensor Test

These systems have a second test mode that helps separate a bad sensor from a bad ring. Toyota's course describes eight extra codes, 71 through 78, that report either a low output voltage from a speed sensor (71-74, pointing at the sensor or its installation) or an abnormal change in output voltage (75-78, pointing at that wheel's sensor rotor). The check is entered by jumpering terminals Ts and E1, and the entry procedure differs by model and year; on some early models the parking brake and service brake are used to enter the mode. Drive straight ahead during the test and follow your repair manual for the exact steps.

Clearing the Codes After the Repair

Stored codes stay in memory after you fix the problem. Toyota's typical clearing procedure:

1. Jumper Tc and E1, and remove the short pin from DLC1 if your car has one.
2. Turn the ignition on.
3. Press the brake pedal 8 or more times within 3 seconds, letting it return fully each time so the brake light switch opens and closes.
4. Confirm the light now shows the normal two-per-second blink.
5. Remove the jumper and reinstall the short pin.

If the code does not clear, cycle the ignition off and back on and repeat the pedal presses. If the light comes back after a test drive, the fault is still present.

What to Replace at the Same Time

ABS work on these cars often happens alongside a brake job, because the sensor tip sits right next to the rotor and collects its wear debris. If your brake rotors are scored or worn and the pads are semi-metallic, clean the sensor tip while the wheel is off and consider fresh brake pads and rotors so worn parts are not feeding metal dust back onto the sensor. Replace worn clips and slide hardware with a brake hardware kit while you are there. When a sensor must come out, clean its mounting bore so it seats fully; a sensor sitting even slightly proud increases the air gap and can bring the code right back.

How hard is the job? Reading codes needs only a jumper wire. Cleaning a sensor tip or replacing a bolt-in sensor is a driveway job with basic hand tools and an ohmmeter. Tone ring replacement can involve pressing parts on the axle or hub, which is a bigger job, and actuator or ECU work is best done with the factory repair manual in hand. You can browse replacement parts in our brake parts collection.

Frequently Asked Questions

Is it safe to drive a 1990-1997 Camry with the ABS light on?

The ABS computer disables anti-lock when it sets the light, so the car brakes like a non-ABS vehicle and the wheels can lock in a hard stop. If the red BRAKE light is also on, stop and check the fluid level and the parking brake before driving.

Do I need a scan tool to read ABS codes on this Camry?

No. Jumper terminals Tc and E1 at the data link connector with the ignition on, and the ABS light flashes the codes. Remove the short pin first if your car has one.

What does a steady fast blink mean when I jumper Tc and E1?

A steady blink of two times per second after a short pause is the normal code. It means no ABS fault is stored.

Can new brake pads or rotors turn the ABS light on?

They can if the sensor or its wiring is disturbed during the job, or if metal debris ends up on the magnetic sensor tip. Check the sensor connector and clean the tip before reassembling.

Will disconnecting the battery clear the ABS light?

Toyota's documented method is the Tc and E1 jumper with 8 or more pedal presses in 3 seconds. If the underlying fault is still there, the light returns regardless of how the code was cleared.

Sources

1. Toyota / Lexus Technical Training, Section 10 ABS Diagnosis - self-check, Tc/E1 code reading, Camry Bosch no-short-pin note, code chart, 71-78 sensor codes, clearing procedure
2. Brake and Front End - Diagnosing Wheel Speed Sensors - passive sensor operation, air gap range, AC output, tone ring runout, causes of weak signal
3. Brake and Front End - Diagnosis of Faulty ABS Systems - wheel speed sensors as the most common ABS failure
4. Brake and Front End - Wheel Speed Sensors - tone ring nicks, air gap, corroded connectors
5. Troubleshoot My Vehicle - 1992-1995 2.2L Camry code retrieval - in-cabin data link connector location under the driver's dash