P0842 - Transmission Fluid Pressure Sensor Circuit Range/Performance Problem in Common Vehicles like Toyota, Honda, and Ford

Quick Answer

P0842 means: P0842 indicates a problem with the transmission fluid pressure sensor circuit.

Fix: Check and replace faulty components Cost: $150 - $300 Time: 90-180 minutes

Can I drive with P0842? It is advisable to address this issue immediately to prevent further transmission damage.

Common Questions

What does P0842 mean and how does it affect my car?

The P0842 code signifies a malfunction in the transmission fluid pressure sensor circuit, impacting your vehicle's ability to shift gears smoothly. If ignored, it could lead to transmission failure, causing not just performance issues but potentially costly repairs down the line.

What are the most common causes of P0842 and how much does it cost to fix?

The most common cause of the P0842 code is a faulty transmission fluid pressure sensor, which can cost between $150 to $300 to replace. Other issues, such as wiring problems or low fluid levels, can also trigger this code and may require additional costs for repairs.

Can I drive my car with P0842 or should I stop immediately?

It's advisable to stop driving your vehicle soon after the P0842 code appears. Continuing to drive can lead to severe transmission damage, which can be costly to repair.

How can I diagnose P0842 myself using GeekOBD APP?

To diagnose P0842 using the GeekOBD APP, first, connect the OBD2 scanner to your vehicle's port. Use the app to read the fault codes and check the freeze frame data to analyze the conditions when the code was triggered. Pay attention to the transmission fluid pressure sensor readings for any anomalies.

What vehicles are most commonly affected by P0842?

The P0842 code is commonly seen in vehicles such as the 2005-2010 Honda Civic, 2010-2015 Ford Fusion, and 2007-2012 Toyota Camry. It's essential to check if your vehicle has any recalls or technical service bulletins related to this code.

How can I prevent P0842 from happening again?

Regular maintenance, including routine transmission fluid changes and inspections of the wiring and connectors, can help prevent the P0842 code from recurring. Keeping an eye on fluid levels and quality can also mitigate potential issues.

What is P0842?

The P0842 diagnostic trouble code (DTC) indicates a problem with the transmission fluid pressure sensor circuit, which measures the hydraulic pressure in the transmission system. This sensor is crucial for the transmission control module (TCM) to make informed decisions about shifting gears and maintaining proper transmission operation. When this code appears, it typically means that the TCM has detected a signal outside the expected range from the sensor, indicating either a malfunctioning sensor or an issue within the circuit itself. This code is prevalent in various vehicles, including 2005-2010 Honda Civics, 2010-2015 Ford Fusions, and 2007-2012 Toyota Camrys. If left unaddressed, a P0842 code can lead to serious transmission issues such as slipping, erratic shifting, or complete transmission failure, resulting in costly repairs. Therefore, understanding this code and its implications is crucial for maintaining your vehicle's performance and longevity.

System: P - Powertrain (Engine, Transmission, Emissions)

Symptoms

Common symptoms when P0842 is present:

  • Check engine light illuminates or blinks, indicating potential transmission issues that need attention.
  • Transmission experiences delayed shifting, causing a noticeable lag when changing gears during acceleration.
  • Vehicle may hesitate or jerk during acceleration, leading to an uncomfortable driving experience.
  • Decrease in fuel economy, potentially by 10-15%, due to transmission inefficiency.
  • Strange noises or grinding sounds from the transmission area, indicating potential internal damage.

Possible Causes

Most common causes of P0842 (ordered by frequency):

  1. Faulty transmission fluid pressure sensor (most common cause, 60% likelihood) - A malfunctioning sensor can send incorrect data to the TCM, causing erratic behavior.
  2. Wiring issues or corroded connectors (20% likelihood) - Damaged wiring or loose connections can interrupt the signal between the sensor and TCM.
  3. Low transmission fluid levels or dirty fluid (10% likelihood) - Insufficient or contaminated fluid can affect sensor operation and overall transmission performance.
  4. Faulty TCM (5% likelihood) - Although rare, a defective TCM can misinterpret sensor readings, triggering the P0842 code.
  5. Transmission internal failure (5% likelihood) - Serious issues within the transmission can also lead to incorrect pressure readings and this DTC.

P0842 Repair Costs

Cost Breakdown by Repair Type

Transmission Fluid Pressure Sensor Replacement

Replacing the faulty transmission fluid pressure sensor with a genuine or high-quality aftermarket part.

  • Total: $150 - $300
  • Success rate: 85%
Wiring Repair

Repairing or replacing damaged wiring or connectors in the transmission pressure sensor circuit.

  • Total: $100 - $250
  • Success rate: 75%
Transmission Fluid Change

Performing a transmission fluid change if low or dirty fluid is a contributing factor.

  • Total: $80 - $150
  • Success rate: 60%
Money-Saving Tips for P0842
  • 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 P0842 Diagnosis Process

Follow these systematic steps to accurately diagnose P0842. 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).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
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).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 3: Step 3: Component testing - Use a multimeter or specific diagnostic tools to test the transmission fluid pressure sensor and related wiring (20-30 minutes)

Step 3: Component testing - Use a multimeter or specific diagnostic tools to test the transmission fluid pressure sensor and related wiring (20-30 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 4: Step 4: System function test - Verify proper operation after repairs and clear codes using the GeekOBD APP (10-15 minutes)

Step 4: System function test - Verify proper operation after repairs and clear codes using the GeekOBD APP (10-15 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 5: Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success and ensure normal operation (15-20 minutes)

Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success and ensure normal operation (15-20 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.

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 Pressure Sensor Replacement on 2010 Honda Civic

Vehicle: 2010 Honda Civic, 85,000 miles

Problem: Customer reported the check engine light was on and noticed delayed shifting.

Diagnosis: OBD2 scan revealed a P0842 code. Visual inspection showed corroded wiring to the sensor.

Solution: Repaired the wiring and replaced the transmission fluid pressure sensor. Cleared the codes and conducted a road test.

Cost: $220 (sensor: $150, labor: $70)

Result: After the repair, the vehicle shifted smoothly, and the check engine light remained off.

Case Study 2: Wiring Issues in 2012 Ford Fusion

Vehicle: 2012 Ford Fusion, 90,000 miles

Problem: Customer complained of a check engine light and transmission slipping.

Diagnosis: P0842 code confirmed; inspection located a damaged wire in the sensor circuit.

Solution: Repaired the damaged wiring and conducted a transmission fluid change.

Cost: $180 (wiring repair: $100, fluid change: $80)

Result: Transmission performance improved significantly, and the check engine light stayed off.

Diagnose P0842

Use GeekOBD APP for professional diagnosis!

  • Real-time data monitoring
  • Advanced diagnostic features
  • Step-by-step repair guidance
  • Professional-grade analysis
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Code Information

Code: P0842
System: Powertrain (Engine, Transmission, Emissions)
Severity: HIGH
Category: Engine Codes