P0973 — Shift Solenoid “A” Control Circuit Low #

Note: The code label may vary depending on the vehicle manufacturer (OEM).

• P0973 – Shift Solenoid ‘A’ Control Circuit Low (GM, Ford, Chrysler)
• P0973 – Shift Solenoid A Electrical Circuit Low (Toyota, Honda, Nissan)
• P0973 – Shift Solenoid A Short to Ground (Hyundai, Kia)

Summary of Code P0973 #

P0973 is a diagnostic trouble code (DTC) that indicates a low voltage condition in the control circuit of shift solenoid “A” within the automatic transmission system. The shift solenoid is an electromechanical valve responsible for controlling the flow of transmission fluid, which in turn manages gear changes. When the powertrain control module (PCM) or transmission control module (TCM) detects that the electrical voltage on the “A” solenoid’s control circuit is lower than the specified threshold, it triggers this code. This issue can affect shifting performance and may lead to transmission-related drivability problems. Addressing P0973 quickly can help prevent further transmission damage and avoid costly repairs.

Common Symptoms for Code P0973 #

When P0973 is present, your vehicle may exhibit several noticeable symptoms, ranging from mild to severe. These symptoms often reflect the shift solenoid’s inability to operate as intended, leading to abnormal gear shifts or even a lack of shifting altogether. The presence and severity of symptoms can vary based on the make and model, but the following are most frequently observed:

• Check Engine Light (CEL) illuminated
• Harsh, delayed, or erratic gear shifts
• Transmission stuck in a single gear (often limp mode)
• Decreased fuel efficiency
• Failure to engage certain gears (typically first or second)
• Possible transmission overheating

Probable Causes for Code P0973 #

The most common causes of P0973 relate to the electrical or mechanical integrity of the shift solenoid “A” circuit. Some causes are straightforward, such as a faulty solenoid, while others may involve more complex wiring or control module issues. Here are the most likely culprits, ranked by frequency:

1. Faulty shift solenoid “A” (internal short or coil failure)
2. Damaged, corroded, or loose wiring/connectors in the solenoid’s circuit
3. Short to ground in the solenoid control circuit
4. Low system voltage or weak battery
5. Faulty PCM or TCM (rare)
6. Internal transmission wiring harness issues

Step-by-Step Diagnostic for Code P0973 #

Diagnosing P0973 requires a methodical approach to avoid replacing parts unnecessarily. Here’s a logical step-by-step process trusted by OEM technicians:

• 1. Scan for additional DTCs to see if other transmission-related codes are present.
• 2. Inspect transmission fluid level and condition to rule out fluid-related issues.
• 3. Visually inspect wiring and connectors at the transmission and solenoid for damage, corrosion, or loose connections.
• 4. Test battery voltage to ensure proper system voltage supply.
• 5. Use a multimeter to check for continuity and shorts in the shift solenoid “A” circuit.
• 6. Perform a resistance test on shift solenoid “A” to verify it is within OEM specifications.
• 7. Command solenoid activation with a scan tool and observe response.
• 8. If no faults found, consider PCM/TCM diagnosis and perform a pinpoint test as per OEM service manual.

Possible Repairs for Code P0973 #

Once the root cause is identified, repairs for P0973 can be straightforward or may require more in-depth intervention. Always clear the code and test drive the vehicle after repairs to confirm resolution. Common fixes include:

• Replace faulty shift solenoid “A”
• Repair or replace damaged wiring/connectors in the solenoid circuit
• Fix short to ground in the control circuit
• Replace blown fuses or relays as needed
• Charge or replace a weak battery
• Replace or reprogram PCM/TCM (only after confirming all other components are functional)

Is It Safe to Drive with Code P0973? #

Limited – With Caution. While your vehicle may still operate with P0973, shifting issues can lead to further transmission damage, reduced power, and potential safety risks, especially if the car is stuck in a single gear or enters limp mode. It’s best to avoid long trips, heavy loads, or highway driving until repairs are made. Prompt attention is highly recommended to prevent more severe transmission failure.

Vehicles Most Commonly Affected by Code P0973 #

While P0973 can appear in any modern vehicle with electronically controlled automatic transmissions, it is most frequently reported on models from the following brands:

• Chevrolet (Malibu, Impala, Silverado, Cruze)
• Ford (Fusion, Escape, F-150, Focus)
• Honda (Accord, Civic, Odyssey)
• Toyota (Camry, Corolla, Tacoma)
• Nissan (Altima, Sentra, Rogue)
• Hyundai and Kia (Sonata, Elantra, Optima)
• Chrysler, Dodge, Jeep vehicles with automatic transmissions

Common Mistakes & Best Practices for Code P0973 #

A few pitfalls can prolong repairs or lead to repeated code returns. Here’s what to watch for, along with some expert-approved tips:

• Replacing the solenoid without checking wiring—always verify circuit integrity first.
• Overlooking poor battery or charging system condition.
• Ignoring related DTCs that may point to a broader transmission issue.
• Skipping a visual inspection—sometimes the problem is as simple as a loose connector.
• Not following OEM test procedures, especially for resistance and continuity checks.

Express FAQ for Code P0973 #

Q: Can a bad shift solenoid cause permanent transmission damage?
A: If left unaddressed, a malfunctioning shift solenoid can cause abnormal shifting, which may lead to internal wear or overheating, potentially resulting in costly repairs.

Q: Will clearing the code fix the problem?
A: Clearing the code will temporarily turn off the warning light, but if the underlying issue isn’t fixed, the code and symptoms will return almost immediately.