P0740 Code: Toyota Camry (2018-2024) - Causes, Symptoms & Fixes

Comprehensive diagnostic guide for OBD-II code P0740 on 2018-2024 Toyota Camry

Note on data sources

• The provided NHTSA dataset shows one owner complaint for P0442 (not P0740) and reports no recalls for this model/year. There are no P0740 complaints or recalls listed in the data you supplied. This guide uses general Toyota/Camry transmission knowledge in addition to the diagnostic steps you would expect for P0740 in this vehicle range.

Code meaning and severity

• Code: P0740 — Torque Converter Clutch (TCC) Circuit Malfunction
• What it means: The Transmission Control Module (TCM) detects a fault in the circuit that controls the torque converter clutch. This can involve the TCC solenoid, wiring, grounds, or the TCM’s ability to command and monitor lockup.
• Severity and symptoms: Moderate to high. Loss of TCC lockup can reduce fuel economy and heat the transmission, and a stuck or intermittent TCC can cause shudder, slipping, or harsh shifting. If the TCC cannot engage or disengage properly, you may notice poor acceleration, higher engine RPM at cruising speeds, or a reminder light on the dashboard. Prolonged operation with a faulty TCC can lead to overheating and transmission damage.

Common causes on the Toyota Camry (2018–2024)

• Faulty TCC solenoid or solenoid circuit (open/short to ground, high resistance, or PWM control issue)
• Damaged or corroded wiring/connectors between the TCM and the TCC solenoid (including insulation wear or pins loosened)
• Transmission Control Module (TCM) faults or software issues requiring an update or reflash
• Torque converter or lockup clutch internal wear or damage
• Dirty or contaminated transmission fluid, or incorrect ATF specification (wrong fluid type or degraded fluid)
• Transmission valve body wear or debris impeding hydraulic control of the TCC
• Excessive transmission fluid temperature or overheating
• Other related transmission codes (e.g., P0741/P0742) indicating solenoid or circuit performance problems
• In rare cases, mechanical installation or aftermarket modifications affecting transmission electronics

Symptoms you might observe

• Check Engine Light (CEL) with P0740 stored or pending
• Reduced fuel economy due to loss of lockup at highway speeds
• Intermittent or permanent lack of TCC lockup, resulting in higher RPMs at steady highway speeds
• Shuddering or harsh engagement when abrupt locking/unlocking occurs
• Inconsistent or poor acceleration performance
• Transmission overheating or shifting irregularities
• In some cases, the car may run normally at times and then exhibit symptoms later

Diagnostic steps (structured approach)

Note: Some steps require advanced scan tools and transmission test equipment. If you’re not comfortable performing certain tests, consult a qualified technician.

A. Confirm and collect data

• Use an advanced OBD-II scanner to confirm P0740 and check for any related codes (P0741, P0742, P0770 family, P0700, etc.). Note any freeze-frame data.
• Check for active/ pending codes and read live data (if possible): TCC solenoid duty cycle, TCC lockup status, transmission fluid temperature, line pressure, TCM fault codes, and vehicle speed vs. engine RPM.

B. Visual and basic checks

• Inspect the TCC wiring harness and connectors at the transmission and at the TCM for damaged insulation, corrosion, loose pins, or obvious wear.
• Inspect the transmission oil level and condition. Confirm you are using the correct Toyota WS ATF (or the fluid specified in the owner’s manual). Look for burnt smell, dark color or metallic debris in the fluid.
• Check for any transmission fluid leaks around the valve body, pan, cooler lines, and torque converter area.

C. Fluid, pressure, and sensor verification

• Fluid condition and level: If low or degraded, replace with the correct ATF and ensure proper level after the vehicle reaches operating temperature. Do not mix fluids.
• Transmission fluid temperature: Ensure the transmission is adequately warmed up during tests; a cold test can mislead results.
• Live data test (if equipped): Monitor the TCC solenoid PWM (duty cycle) andlockup status as the TCM commands engage/disengage. Look for abnormal duty cycles, delay, or failure to engage lockup.
• If accessible, perform a line pressure test in the transmission (requires professional equipment). Compare readings to Toyota service data/specs for the Camry 8AT. Abnormally low or unstable line pressure can indicate internal hydraulic problems or valve body wear.

D. Electrical tests

• Inspect and test harness continuity from the TCM to the TCC solenoid. Look for short to ground, short to power, or open circuits.
• Check ground connections to the transmission and TCM. A bad ground can cause intermittent solenoid operation.
• If the vehicle supports it, perform a TCM re-flash or software update if indicated by Toyota service information. Some cases resolve with software updates.

E. Rule-out related codes

• Scan for P0741, P0742 (Torque Converter Clutch Solenoid Performance/Range) or other torque converter/HCU/valve body related codes. Addressing a solenoid or hydraulic issue may resolve P0740 without further action.
• If no other codes point to an electrical or hydraulic fault, proceed to more in-depth transmission diagnostics.

F. Repair-path decision tree

• If a faulty TCC solenoid or wiring is found: Replace the solenoid or repair wiring, recheck for code clearance, and test drive to confirm.
• If hydraulic pressure tests show valve body or pump issues: Valve body cleaning or replacement, or addressing solenoid logic may be required.
• If transmission fluid is degraded or incorrect: Flush or replace with the correct ATF and monitor performance; ensure cooling system is functioning to prevent overheating.
• If a mechanical failure within the torque converter or transmission is detected (wear, damaged clutch packs, or transaxle wear): Assess repair vs. replacement. In some cases, a complete transmission rebuild or replacement is necessary.
• If TCM software update is available and applicable: Perform update; re-test to verify resolution.
• If all electrical and hydraulic tests pass and the vehicle shows no symptoms after repair, clear the codes and monitor for recurrence.

Related codes (context and cross-reference)

• P0700 (Transmission Control System Malfunction) can accompany P0740 in some cases.
• P0741/P0742 (Torque Converter Clutch Solenoid Performance/Range) are commonly considered as related torque-converter circuit codes.
• Other P07xx codes may indicate transmission hydraulics, solenoids, or module issues. Always review the full code set when diagnosing.

Repair options and costs (2025 prices)

Note: Prices are approximate ranges for the United States and can vary by region, shop, and vehicle condition. Labor rates commonly range around $100–$180 per hour in many shops.

• TCC solenoid replacement

  • Parts: $25–$150
  • Labor: 1–3 hours
  • Estimated total: $150–$550

• TCC solenoid harness/wiring repair

  • Parts: minimal (connector/section of harness)
  • Labor: 1–3 hours
  • Estimated total: $120–$500

• Transmission fluid and drain/fill service with correct ATF (WS or Toyota-recommended)

  • Parts: $6–$15 per quart; total expected 6–12 quarts
  • Fluid cost: $36–$180
  • Labor: 0.5–1.5 hours
  • Estimated total: $80–$350

• Valve body cleaning or replacement (if hydraulic issues are found)

  • Parts: $150–$600 (valve body assembly)
  • Labor: 4–8 hours
  • Estimated total: $600–$2,400

• Torque converter replacement (if needed)

  • Parts: $250–$900 (depends on model and supply)
  • Labor: 6–12 hours
  • Estimated total: $1,500–$4,000

• Transmission control module (TCM) update or replacement

  • Software update (if available): often $0–$150 at dealer for update
  • TCM replacement: Parts $300–$900; labor 1–4 hours
  • Estimated total: $300–$1,800

• Transmission replacement or rebuild (last-resort option)

  • Parts: 1,000–2,500+ (core price varies by remanufacturer)
  • Labor: 8–12+ hours
  • Estimated total: $3,000–$8,000+

• Note on cost ranges: If you’re near a dealer, prices can be higher; independent shops may be cheaper but ensure they have proper transmission experience. Any major repair (valve body, torque converter, or transmission replacement) should include a warranty on parts and labor.

DIY vs professional

• DIY feasible/components you might handle:

  • Checking and topping off the correct ATF with the car on level ground when warm
  • Inspecting obvious wiring harness connections and grounds
  • Reading and interpreting live data with a capable scan tool
  • Replacing TCC solenoid if you have the right tools and transmission access (some Camry models place the solenoid behind the valve body; visibility may require pan drop)
  • Replacing ATF and performing a shallow pan gasket inspection (on some models)

• Professional considerations:

  • Many P0740 scenarios require precise line pressure checks, solenoid diagnostics, valve-body inspection, and sometimes internal transmission work. This typically requires specialized tools, a safe elevated stance, and knowledge of Toyota 8AT service procedures.
  • If the issue involves valve body cleaning or torque converter replacement, professional service is advisable to avoid misdiagnosis and potential collateral damage.
  • A dealer or transmission specialist can also perform software updates or TCM re-flashing as needed.

Prevention and maintenance

• Use the manufacturer-recommended ATF (Toyota WS or equivalent approved fluid) and avoid mixing fluids or using general-purpose substitutes.
• Regular transmission fluid service per Toyota’s recommended schedule (intervals vary by model/year; when in doubt, follow the owner’s manual or dealership guidance).
• Monitor transmission temperatures in hot climates or heavy towing scenarios; ensure the external oil cooler lines and radiator cooling system are functioning properly to prevent overheating.
• Address small transmission or electrical issues promptly; small o-ring leaks, poor voltage, or corroded connectors can escalate into bigger problems.
• Keep the vehicle's software up to date with Toyota-released TCM updates, as they can improve torque-converter operation and fault handling.

Important data note

• The dataset you provided shows no P0740 complaints and no recalls for 2018–2024 Camry in NHTSA data. This guide uses standard diagnostic practice for P0740 in Camry models, with practical cost ranges for 2025 and caveats about regional variation and vehicle condition.

If you’d like, I can tailor this guide to your specific Camry variant (2.5L four-cylinder vs. other engine/transmission combinations) and your region, and provide a condensed, step-by-step handout you could print for a shop visit.