P0858 - Transmission Range Sensor Circuit High Input - Common in 2005-2010 Ford F-150 and 2007-2013 Chevrolet Silverado

Quick Answer

P0858 means: DTC P0858 signifies a high input signal from the transmission range sensor, indicating potential issues with gear selection.

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

Can I drive with P0858? It is advisable to address this issue immediately to prevent further transmission damage.

Common Questions

What does P0858 mean and how does it affect my car?

DTC P0858 indicates a high input signal from the transmission range sensor, which affects the vehicle's ability to start and shift gears correctly. Over time, this can lead to severe transmission issues, reduced performance, and safety risks while driving.

What are the most common causes of P0858 and how much does it cost to fix?

The most common causes include a faulty transmission range sensor, wiring issues, and low transmission fluid. Repair costs can range from $100 for wiring repairs to $1,500 for ECM replacement, depending on the severity of the issue.

Can I drive my car with P0858 or should I stop immediately?

While you may be able to drive the vehicle, it is not recommended to ignore the P0858 code. Continuing to drive could lead to more significant transmission damage and costly repairs, so it is best to have it diagnosed and repaired as soon as possible.

How can I diagnose P0858 myself using GeekOBD APP?

Using the GeekOBD APP, you can scan for DTCs and view freeze frame data, which helps you understand the conditions under which the fault occurred. You can also monitor the transmission range sensor's voltage output to pinpoint the issue.

What vehicles are most commonly affected by P0858?

DTC P0858 is commonly found in vehicles like the 2005-2010 Ford F-150 and the 2007-2013 Chevrolet Silverado, along with other models that share similar transmission components.

How can I prevent P0858 from happening again?

To prevent P0858 from reoccurring, regularly check and maintain your vehicle's transmission fluid levels, replace worn components promptly, and have periodic inspections of the wiring and electrical connections associated with the transmission range sensor.

What is P0858?

Diagnostic Trouble Code (DTC) P0858 indicates that the Transmission Range Sensor Circuit is reporting a high input signal to the Engine Control Module (ECM). The transmission range sensor, also known as the neutral safety switch, ensures that the transmission is in the correct gear before allowing the engine to start. When the sensor detects an incorrect signal, it can lead to poor performance or even prevent the vehicle from starting. This code is commonly seen in vehicles such as the 2005-2010 Ford F-150 and the 2007-2013 Chevrolet Silverado. Drivers may experience issues like the engine not starting, erratic shifting, or the check engine light illuminating. Ignoring this code can lead to further transmission complications and costly repairs down the line, making it essential to address promptly. Furthermore, if the vehicle is still operable, you may notice delayed or harsh shifting, which can impact overall driving comfort and safety. In some instances, you might also experience reduced fuel efficiency as the engine struggles to operate under optimal conditions.

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

Symptoms

Common symptoms when P0858 is present:

  • Check engine light stays on constantly, indicating an electrical fault with the transmission range sensor.
  • Engine hesitates during acceleration, making it difficult to smoothly change gears.
  • Fuel economy decreased by 10-15%, reflecting inefficiencies due to improper gear selection.
  • Delayed engagement when shifting from park to drive, which can affect driving safety.
  • Erratic shifting behavior, where the transmission shifts unexpectedly, causing discomfort while driving.

Possible Causes

Most common causes of P0858 (ordered by frequency):

  1. The most common cause is a malfunctioning transmission range sensor, with a likelihood of 60%. This sensor can wear over time or become misaligned.
  2. A second cause could be wiring issues such as frayed or damaged wires affecting the sensor's signaling, which can lead to poor electrical connections.
  3. A third cause may involve low transmission fluid levels, which can cause erratic shifting or improper gear engagement. Regularly check and top off fluids as part of preventive maintenance.
  4. Less common but serious causes include a failing Engine Control Module (ECM) that misinterprets sensor data, leading to potentially expensive repairs.
  5. A rare but possible cause is internal transmission damage, which can result from neglecting routine maintenance and can cost thousands to repair.

P0858 Repair Costs

Cost Breakdown by Repair Type

Replace Transmission Range Sensor

Replacing the faulty transmission range sensor to restore proper gear signaling.

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

Fixing or replacing damaged wiring to ensure proper electrical connectivity.

  • Total: $100 - $250
  • Success rate: 75%
Replace ECM

Replacing a failed Engine Control Module if it is determined to be the source of the issue.

  • Total: $800 - $1,500
  • Success rate: 90%
Money-Saving Tips for P0858
  • 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 P0858 Diagnosis Process

Follow these systematic steps to accurately diagnose P0858. 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 voltage output of the transmission range sensor (20-30 minutes)

Step 3: Component testing - Use a multimeter or specific diagnostic tools to test the voltage output of the transmission range sensor (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 proper shifting (15-20 minutes)

Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success and ensure proper shifting (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 Range Sensor Replacement on 2008 Ford F-150

Vehicle: 2008 Ford F-150, 120,000 miles

Problem: Customer reported the check engine light was on and the vehicle hesitated during shifting.

Diagnosis: Performed OBD2 scan with GeekOBD APP, confirmed P0858 code, inspected the transmission range sensor and found it faulty.

Solution: Replaced the transmission range sensor and cleared the codes.

Cost: $250 (sensor $150, labor $100)

Result: Customer reported improved shifting and no further check engine light.

Case Study 2: Wiring Repair on 2011 Chevrolet Silverado

Vehicle: 2011 Chevrolet Silverado, 85,000 miles

Problem: Customer experienced erratic shifting and the check engine light was illuminated.

Diagnosis: Used GeekOBD APP to identify P0858 and inspected wiring for damage.

Solution: Repaired the damaged wiring harness and tested the system.

Cost: $180 (wiring repair $80, labor $100)

Result: Vehicle functioned normally after repairs, with no recurring issues.

Diagnose P0858

Use GeekOBD APP for professional diagnosis!

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

Code: P0858
System: Powertrain (Engine, Transmission, Emissions)
Severity: HIGH
Category: Engine Codes