P0743 on Toyota vehicles
Torque Converter Clutch Circuit Electrical Fault — what it means on a Toyota, whether it's safe to drive, and the fixes by model and year.
P0743 on a Toyota means torque converter clutch circuit electrical fault. Most vehicles stay drivable short-term, but diagnose it promptly. The most common cause is failed tcc solenoid (open or shorted coil) (typically $300–$900). Pick your Toyota model below for its known failure patterns, recalls, and TSBs.
What does P0743 mean on a Toyota?
P0743 narrows the torque converter clutch fault to the electrical circuit specifically. The transmission controller drives the TCC solenoid and monitors that circuit's voltage or current; an open coil, a short to ground, a short to power, or resistance well outside specification will set P0743. It is a wiring-and-solenoid code rather than a "the clutch is worn out" code — though the only way to be sure of that is to test the circuit rather than assume it.
P0743 is a standardized OBD-II code, so its definition is the same on every Toyota. What differs by model and engine is which cause is most likely — pick your Toyota model below for a diagnosis tuned to its known failure patterns, recalls, and TSBs.
Is it safe to drive a Toyota with P0743?
In most cases a Toyota stays drivable for short trips with P0743 active, but diagnose and repair it promptly. This is a high-severity code — ignoring it can lead to further damage or a failed emissions test. Exact tolerance depends on the model and engine.
What causes P0743 on a Toyota?
| Cause | Likelihood | Estimated repair (USD) |
|---|---|---|
| Failed TCC solenoid (open or shorted coil) | Most common | $300–$900 |
| Transmission fluid wicked up the harness into the external connector — Reads identically to a failed solenoid on a multimeter — inspect the connector before ordering parts. | Most common | $100–$500 |
| Chafed, broken, or corroded TCC solenoid wiring | Common | $80–$350 |
| Low or contaminated transmission fluid | Occasional | $100–$400 |
| Failed TCM or PCM driver for the TCC solenoid circuit | Rare | $500–$1,500 |
Repair costs are typical US ranges and vary by Toyota model, model year, and labor rate. A diagnostic trouble code is a symptom, not a guaranteed failed part — confirm the root cause before replacing anything.
P0743 by Toyota model
Select your Toyota model and year for a P0743 diagnosis tuned to that vehicle's failure patterns, recalls, and TSBs.
Toyota RAV4
691 NHTSA owner complaints · 9 recalls on record across the years covered below.
Toyota Camry
842 NHTSA owner complaints · 6 recalls on record across the years covered below.
Toyota Corolla
721 NHTSA owner complaints · 8 recalls on record across the years covered below.
Toyota Tacoma
583 NHTSA owner complaints · 15 recalls on record across the years covered below.
Toyota 4Runner
170 NHTSA owner complaints · 16 recalls on record across the years covered below.
Toyota Highlander
650 NHTSA owner complaints · 11 recalls on record across the years covered below.
Toyota Sienna
393 NHTSA owner complaints · 22 recalls on record across the years covered below.
Complaint and recall counts are NHTSA totals for the model years covered on this site, not counts specific to P0743.
P0743 on other makes
Other codes on Toyota vehicles
P0743 on a Toyota: frequently asked questions
What does diagnostic trouble code P0743 mean on a Toyota?
P0743 narrows the torque converter clutch fault to the electrical circuit specifically. The transmission controller drives the TCC solenoid and monitors that circuit's voltage or current; an open coil, a short to ground, a short to power, or resistance well outside specification will set P0743. It is a wiring-and-solenoid code rather than a "the clutch is worn out" code — though the only way to be sure of that is to test the circuit rather than assume it. P0743 is a standardized OBD-II code, so the definition is the same on every Toyota — which cause is most likely varies by model and engine.
What are the symptoms of P0743 on a Toyota?
Check Engine Light is illuminated. Engine RPM at highway cruise higher than normal for the same speed. Noticeable fuel economy drop on the highway. No sensation of lockup engaging at cruising speed. Transmission fluid running hot, particularly when towing. Often paired with P0700 from the transmission controller
What causes P0743 on a Toyota?
Failed TCC solenoid (open or shorted coil) (most-common). Transmission fluid wicked up the harness into the external connector (most-common). Chafed, broken, or corroded TCC solenoid wiring (common). Low or contaminated transmission fluid (occasional). Failed TCM or PCM driver for the TCC solenoid circuit (rare)
Is it safe to drive a Toyota with P0743?
In most cases a Toyota stays drivable for short trips with P0743 active, but it should be diagnosed and repaired promptly — this is a high-severity code. Ignoring it can lead to further damage or a failed emissions test. Exact tolerance depends on the model and engine.