Safety Warning
- Vehicle may experience unpredictable shifting, sudden loss of power, or inability to shift into certain gears
- Do not continue driving if transmission is slipping, making loud noises, or failing to engage gears
- Avoid highway driving until diagnosis is complete
Quick Diagnosis Summary
The P0700 diagnostic trouble code in your 2020 Chevrolet Traverse indicates a transmission control system malfunction that requires immediate attention. This generic OBD-II code serves as a gateway code, alerting you that your vehicle's Transmission Control Module (TCM) has detected an issue within the transmission system and has stored additional, more specific trouble codes.
While the P0700 code itself doesn't pinpoint the exact problem, it's your transmission's way of saying "something's wrong, and you need to dig deeper." Understanding this code and its implications can help you make informed decisions about repairs and avoid costly transmission damage.
What Does P0700 Code Mean in Your 2020 Traverse?
The P0700 code specifically means "Transmission Control System Malfunction." In your 2020 Chevrolet Traverse, this code indicates that the Powertrain Control Module (PCM) has detected that the TCM has set one or more transmission-related diagnostic trouble codes. The TCM continuously monitors various sensors, solenoids, and circuits within the transmission system.
When the TCM detects abnormal readings or component failures, it stores specific codes and triggers the P0700 as a notification to the main computer system. This is why professional diagnosis typically reveals additional codes that provide more detailed information about the actual problem.
Symptoms of P0700 Code in 2020 Chevrolet Traverse
Drivers experiencing P0700 code issues in their 2020 Traverse typically notice several warning signs:
- Check Engine Light: The most obvious symptom, though it may appear intermittently at first
- Transmission Warning Light: May illuminate on the dashboard alongside or instead of the check engine light
- Harsh or Delayed Shifting: Transmission may shift roughly between gears or hesitate before engaging
- Stuck in One Gear: Transmission may fail to shift out of a particular gear, often defaulting to "limp mode"
- Slipping Transmission: Engine RPMs increase without corresponding acceleration
- Unusual Noises: Whining, grinding, or clunking sounds during gear changes
- Poor Fuel Economy: Decreased gas mileage due to improper gear ratios
- Inability to Start: In severe cases, the vehicle may not start or may start but not move
Common Causes of P0700 Code in 2020 Traverse
Transmission Control Module (TCM) Failure
The most common cause in 2020 Traverse models is TCM failure. The TCM contains complex circuitry and software that can develop internal faults over time. Chevrolet has acknowledged issues with TCM reliability in some 2020 Traverse models, particularly those with high mileage or exposure to extreme temperatures. Symptoms of TCM failure include erratic shifting patterns and multiple transmission codes appearing simultaneously.
Faulty Transmission Solenoids
Transmission solenoids control fluid flow within the transmission, enabling smooth gear changes. In the 2020 Traverse's 9-speed automatic transmission, several solenoids work together to manage shifting. When one or more solenoids fail due to electrical issues or mechanical wear, the TCM detects abnormal pressure readings and triggers the P0700 code along with specific solenoid codes.
Wiring Harness Problems
The complex wiring between the TCM and transmission components can develop issues over time. Corrosion at connector points, especially in areas exposed to road salt or moisture, can interrupt communication. Rodent damage to wiring harnesses is also common, particularly in vehicles parked outdoors or in rural areas.
Low or Contaminated Transmission Fluid
Transmission fluid serves multiple purposes: lubrication, cooling, and hydraulic pressure. Low fluid levels or contaminated fluid can cause pressure irregularities that the TCM interprets as system malfunctions. The 2020 Traverse requires specific Dexron VI automatic transmission fluid, and using incorrect fluid types can also trigger this code.
Internal Transmission Mechanical Issues
While less common in newer vehicles like the 2020 Traverse, internal mechanical problems such as worn clutch packs or valve body issues can cause the TCM to detect abnormal operation patterns and set the P0700 code.
Diagnosing P0700 Code in Your 2020 Traverse
Professional diagnosis begins with connecting an advanced OBD-II scanner capable of reading manufacturer-specific codes. Basic code readers may only show the P0700 code, but professional-grade scanners reveal the additional codes stored in the TCM that provide specific failure information.
The diagnostic process typically includes:
- Code Reading: Retrieving all stored codes from both PCM and TCM
- Fluid Inspection: Checking transmission fluid level, color, and condition
- Visual Inspection: Examining wiring harnesses and connectors for damage
- Electrical Testing: Testing solenoid resistance and TCM power/ground circuits
- Road Testing: Operating the vehicle to observe transmission behavior
- TCM Functionality Test: Using specialized equipment to test TCM responses
Repair Options and Costs
Professional Repair
Professional repair is highly recommended for P0700 code issues due to the complexity of modern transmission systems. Certified technicians have access to manufacturer-specific diagnostic equipment and technical bulletins that may apply to your specific vehicle.
Professional repair costs typically range from $800 to $1,500, depending on the root cause:
- TCM Replacement/Reprogramming: $600-$1,200
- Solenoid Replacement: $300-$800
- Wiring Repair: $200-$500
- Transmission Service: $150-$300
DIY Limitations
DIY repair of P0700 code issues is generally not recommended due to:
- Need for specialized diagnostic equipment
- Requirement for TCM programming and calibration
- Risk of causing additional damage
- Complexity of transmission removal if needed
- Warranty considerations on newer vehicles
The only DIY-friendly step is checking and changing transmission fluid, which should be done following manufacturer specifications.
Prevention Tips
Preventing P0700 code issues in your 2020 Traverse involves regular maintenance and careful operation:
- Follow Service Intervals: Adhere to Chevrolet's recommended transmission service schedule
- Use Correct Fluid: Only use Dexron VI automatic transmission fluid
- Monitor Fluid Levels: Check transmission fluid monthly when the engine is warm
- Address Issues Early: Don't ignore unusual shifting or noises
- Avoid Aggressive Driving: Excessive towing or rapid acceleration can stress transmission components
- Keep Records: Document any transmission-related repairs or services
When to Seek Immediate Help
Stop driving immediately and seek professional help if you experience:
- Complete loss of forward or reverse gears
- Severe transmission slipping
- Loud grinding or metal-on-metal noises
- Transmission overheating warnings
- Burning smell from the transmission
Continuing to drive with these symptoms can result in complete transmission failure and significantly higher repair costs.
Frequently Asked Questions
You can drive short distances at low speeds for diagnosis, but avoid highway driving and extended trips. The transmission may shift unpredictably or fail to engage certain gears, creating safety risks. Schedule professional diagnosis as soon as possible.
If your 2020 Traverse is still under the 5-year/60,000-mile powertrain warranty, transmission control system issues should be covered. Contact your Chevrolet dealer immediately, as some TCM issues in 2020 models have been addressed through service bulletins.
Repair costs typically range from $800 to $1,500 depending on the root cause. Simple issues like fluid changes cost $150-$300, while TCM replacement can cost $600-$1,200. Solenoid replacement falls in the $300-$800 range.
No, simply clearing the code will not fix the underlying problem. The P0700 code will return once the TCM detects the same malfunction. Clearing codes without proper diagnosis can actually make troubleshooting more difficult for technicians.
Common additional codes include P0751-P0758 (solenoid performance codes), P0962-P0968 (solenoid control circuit codes), and P0877 (transmission fluid pressure sensor codes). These specific codes help technicians identify the exact component causing the problem.
Yes, low, contaminated, or incorrect transmission fluid can cause pressure irregularities that trigger the P0700 code. Always check fluid level and condition first, as this is the simplest and least expensive potential fix. Use only Dexron VI fluid in your 2020 Traverse.