Quick Answer
P0990 means: P0990 indicates a problem with the transmission fluid temperature sensor's performance.
Can I drive with P0990? Immediate diagnosis and repair are recommended to prevent transmission damage.
Common Questions
What does P0990 mean and how does it affect my car?
The P0990 code indicates a problem with the transmission fluid temperature sensor. This can lead to poor transmission performance, such as rough shifting or decreased fuel efficiency. If ignored, it may cause serious transmission damage.
What are the most common causes of P0990 and how much does it cost to fix?
Common causes include a faulty temperature sensor, wiring issues, or contaminated transmission fluid. Repair costs typically range from $150 to $300 for sensor replacement, while wiring repairs may cost between $100 and $200.
Can I drive my car with P0990 or should I stop immediately?
It is advisable to stop driving the vehicle as soon as possible. Ignoring the P0990 code can lead to further transmission damage, increased repair costs, and unsafe driving conditions.
How can I diagnose P0990 myself using GeekOBD APP?
Use the GeekOBD APP to perform an OBD2 scan. Retrieve the DTC codes and freeze frame data, then check the live data for the transmission fluid temperature sensor to see if it operates within normal parameters.
What vehicles are most commonly affected by P0990?
The P0990 code is frequently seen in 2013-2016 Honda Accords and 2014-2018 Toyota Corollas. It's essential to check for any recalls or Technical Service Bulletins (TSBs) related to these models.
How can I prevent P0990 from happening again?
Regular maintenance, including fluid changes, wiring inspections, and sensor checks, can help prevent P0990 from reoccurring. Make sure to use quality transmission fluid and keep an eye on any changes in vehicle behavior.
What is P0990?
The Diagnostic Trouble Code (DTC) P0990 indicates that there is a performance issue with the transmission fluid temperature sensor. This sensor is essential for monitoring the temperature of the transmission fluid, which is crucial for optimal transmission performance and durability. When this sensor fails or provides incorrect readings, it can lead to a range of problems including improper shifting, decreased fuel efficiency, or even transmission damage over time. Car owners may notice warning lights on the dashboard, a decrease in acceleration performance, or erratic shifting patterns. Commonly, this issue affects vehicles like the 2013-2016 Honda Accord and the 2014-2018 Toyota Corolla, where the transmission relies heavily on accurate temperature readings for proper operation. If left unaddressed, the P0990 code can lead to more severe transmission problems, ultimately resulting in costly repairs. Therefore, understanding the implications of this code is vital for vehicle maintenance and performance.
System: P - Powertrain (Engine, Transmission, Emissions)
Symptoms
Common symptoms when P0990 is present:
- Check engine light stays on constantly, indicating an issue that needs attention.
- Transmission shifts erratically or harshly, causing a rough driving experience.
- Engine hesitates during acceleration, making it difficult to merge or navigate traffic safely.
- Fuel economy decreases by 10-15%, leading to increased fuel costs.
- Transmission may enter 'limp mode' to protect itself, resulting in reduced power and speed.
Possible Causes
Most common causes of P0990 (ordered by frequency):
- Faulty transmission fluid temperature sensor (common cause, 60% likelihood) - This sensor can fail due to wear and tear or exposure to extreme temperatures, leading to inaccurate readings.
- Wiring issues or poor connections (25% likelihood) - Damaged or corroded wiring can disrupt the signal to the ECU, resulting in code P0990.
- Contaminated transmission fluid (10% likelihood) - Dirty or degraded fluid can affect sensor performance and overall transmission function.
- Failed Transmission Control Module (TCM) (3% likelihood) - In rare cases, the TCM itself may malfunction, leading to incorrect sensor readings.
- Thermal expansion issues (2% likelihood) - Extreme heat can cause components to expand improperly, affecting sensor accuracy.
P0990 Repair Costs
Cost Breakdown by Repair Type
Sensor Replacement
Replacing the faulty transmission fluid temperature sensor.
- Total: $150 - $300
- Success rate: 85%
Wiring Repair
Repairing any damaged wiring or connectors related to the sensor.
- Total: $100 - $200
- Success rate: 75%
Money-Saving Tips for P0990
- Start with the most common and least expensive repairs first
- Use GeekOBD APP to confirm diagnosis before replacing expensive parts
- Consider preventive maintenance to avoid future occurrences
- Compare prices for OEM vs aftermarket parts based on your needs
- Address the issue promptly to prevent more expensive secondary damage
Diagnostic Steps
Professional P0990 Diagnosis Process
Follow these systematic steps to accurately diagnose P0990. Each step builds on the previous one to ensure accurate diagnosis.
Step 1: Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion (5-10 minutes)
Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion (5-10 minutes).
Step 2: Step 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context (10-15 minutes)
Step 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context (10-15 minutes).
Step 3: Step 3: Component testing - Use a multimeter to test the voltage output of the transmission fluid temperature sensor (20-30 minutes)
Step 3: Component testing - Use a multimeter to test the voltage output of the transmission fluid temperature sensor (20-30 minutes).
Step 4: Step 4: System function test - Verify proper operation of the sensor and clear codes (10-15 minutes)
Step 4: System function test - Verify proper operation of the sensor and clear codes (10-15 minutes).
Step 5: Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success (15-20 minutes)
Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success (15-20 minutes).
Important Notes
- Always verify the repair with GeekOBD APP after completing diagnostic steps
- Clear codes and test drive to ensure the problem is resolved
- Address underlying causes to prevent code recurrence
Real Repair Case Studies
Case Study 1: Transmission Fluid Temperature Sensor Replacement in 2014 Honda Accord
Vehicle: 2014 Honda Accord, 75,000 miles
Problem: Customer reported check engine light and rough shifting.
Diagnosis: After running a scan with GeekOBD APP, P0990 was confirmed. Visual inspection revealed a faulty sensor.
Solution: Replaced the transmission fluid temperature sensor and performed a fluid change.
Cost: $250 (sensor: $150, labor: $100)
Result: The customer experienced smooth shifting and improved fuel economy post-repair.
Case Study 2: Wiring Issues on a 2015 Toyota Corolla
Vehicle: 2015 Toyota Corolla, 50,000 miles
Problem: Check engine light and erratic transmission behavior.
Diagnosis: P0990 was detected using GeekOBD APP. Inspection showed damaged wiring near the transmission.
Solution: Repaired wiring connections and validated sensor function.
Cost: $150 (labor: $100, wiring parts: $50)
Result: The issue was resolved, and the vehicle operated normally afterward.