← View Generic P0856 Guide Severity: Medium
🚗 Vehicle-Specific Guide

This guide is customized for your 2020 Chevrolet SILVERADO 1500 PICKUP

P0856: P0856: Transmission Control Module (TCM) Range/Performance Issue

on 2020 Chevrolet SILVERADO 1500 PICKUP

Fix Cost
$200 - $1000
Parts & Labor
Difficulty
3/5
1-2 hours
DIY Possible?
❌ No
Pro recommended
Your Vehicle
2020 Chevrolet
SILVERADO 1500 PICKUP
⚠️

Important for 2020 Chevrolet SILVERADO 1500 PICKUP Owners

Before starting repairs, verify which engine your 2020 Chevrolet SILVERADO 1500 PICKUP has. Check your VIN or engine code to ensure you order the correct parts.

📖 What Does P0856 Mean on 2020 Chevrolet SILVERADO 1500 PICKUP?

The Transmission Control Module (TCM) has detected an issue with the transmission's range and performance, which can cause problems with gear shifting and transmission operation.
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Symptoms

  • • Transmission slips
  • • hesitates
  • • or refuses to engage gears
  • • unusual noises
  • • or the 'check engine' light is illuminated.
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Common Causes

  • • Faulty transmission solenoid
  • • faulty transmission control module
  • • faulty transmission wiring harness
  • • or a problem with the transmission's hydraulic system.
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How to Fix P0856 on 2020 Chevrolet SILVERADO 1500 PICKUP

1. Check the transmission solenoid for proper function and replace if necessary. 2. Inspect the transmission wiring harness for damage or corrosion and repair or replace as needed. 3. Check the transmission fluid level and condition, and top off or change as necessary. 4. If the issue persists, replace the transmission control module.

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Parts for 2020 Chevrolet SILVERADO 1500 PICKUP

Transmission solenoid Shop ↗ Transmission wiring harness Shop ↗ Transmission fluid Shop ↗

Essential Tool

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Related Diagnostic Codes

Other codes that may appear with P0856

P0854 Sequential Code

P0854: Transmission Control Module (TCM) Range/Performance Problem

Medium
P0855 Sequential Code

P0855: Transmission Control Module (TCM) Range/Performance Issue

Medium
P0857 Sequential Code

P0857: Transmission Control Module (TCM) Range/Performance Problem

Medium
P0858 Sequential Code

P0858: Transmission Range Sensor Circuit Malfunction

Medium

💡 Why These Codes Are Related:

  • • Similar Issues: Same root cause or component failure
  • • Related Problems: Often occur together due to system interactions
  • • Sequential Codes: Progressive failure stages or multiple sensors
  • • Same System: Components within the same automotive system