P0773 on 2012-2015 Kia Rio: Shift Solenoid 'E' Failure Causes and Fixes

What's Unique About the 2012-2015 Kia RIO

The 2012-2015 Kia Rio uses a 6-speed automatic transmission (A6GF1), part of Hyundai/Kia's A6 family, which is known for issues with its internal shift solenoids. The problem is so well-documented that Kia issued a Technical Service Bulletin (TSB #TSBTRA051R1) that specifically lists P0773 and a host of other solenoid-related codes (P0741, P0743, P0748, P0753, P0758, P0763, P0768, P1778, and P2709). The bulletin advises technicians to replace the faulty solenoids rather than the much more expensive entire transaxle, indicating a higher-than-average failure rate for this specific component on this platform.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• Check Engine Light is on
• Harsh, jerky, or delayed shifting
• Transmission gets stuck in one gear (limp mode), often 3rd gear
• Transmission slipping between gears
• Vehicle may not shift into or out of a specific gear
• Reduced fuel economy
• Transmission overheating warning light may illuminate

Most Likely Causes

1. Failed Shift Solenoid 'E' 🔴 High Probability → Shop Transmission Valve Body This is a widely recognized issue for this transmission, as confirmed by Kia's own Technical Service Bulletin (TSBTRA051R1), which advises replacing the solenoids for this code. The internal coil windings of the solenoid fail, causing an open or short circuit.
   How to confirm: A mechanic can test the solenoid's resistance with a multimeter after accessing it. For the A6GF1 transmission, the on/off shift solenoids (like 'E', which is a black solenoid) should have a resistance of 10-11 Ohms at 68°F (20°C). A reading significantly outside this range confirms a failed solenoid. The solenoid can also be tested by applying a 12V source to see if it clicks.
   Typical fix: Replace the faulty shift solenoid. It is highly recommended to replace the entire 8-solenoid pack and the internal wire harness assembly at the same time, as the other solenoids may be near failure.
   Est. part cost: $200-$450 (for a complete solenoid kit)
2. Low or Contaminated Transmission Fluid 🟡 Medium Probability → Shop Transmission Assembly While not specific to the Rio, the A6GF1 transmission is sensitive to fluid level and condition. Burnt or contaminated fluid can cause solenoid valves to stick or malfunction mechanically, though P0773 is an electrical code.
   How to confirm: Check the transmission fluid level and condition. The fluid should be at the correct level, red in color, and not smell burnt. This transmission does not have a dipstick, so checking it involves removing a fill plug on the side of the transmission case while the vehicle is level and at operating temperature.
   Typical fix: Perform a transmission fluid drain and fill using fluid that meets Kia's SP-IV specification. This is required anyway if replacing the solenoids.
   Est. part cost: $50-$120
3. Damaged Internal Wiring Harness ⚪ Low Probability The internal wiring harness that connects to the solenoids is submerged in hot transmission fluid and can become brittle or damaged over time, causing an open or short circuit that triggers the P0773 code.
   How to confirm: Visually inspect the wiring harness for cracks, breaks, or burnt sections after removing the transmission pan and valve body. Check for continuity between the TCM connector and the transmission connector with a multimeter.
   Typical fix: Replace the internal transmission wiring harness. This is often done as part of a complete solenoid kit replacement.
   Est. part cost: $150-$400 (harness often included with solenoid kits)
4. Faulty Transmission Control Module (TCM) ⚪ Low Probability → Shop Transmission Assembly
   How to confirm: Requires professional diagnosis after all other potential causes (solenoid, fluid, wiring) have been ruled out.
   Typical fix: Replace and reprogram the Transmission Control Module.
   Est. part cost: $500-$1000

Diagnosis Steps

1. Check the transmission fluid level and condition. Top off or replace if low or dirty with Kia SP-IV compatible fluid. Note: This transmission has no dipstick and must be checked via a fill plug.
2. Use a professional scan tool to check for other transmission-related codes. Confirm P0773 is the primary code.
3. Inspect the external wiring and connectors leading to the transmission for any visible damage, corrosion, or loose connections.
4. If external checks pass, the vehicle should be taken to a professional or prepared for internal transmission work. The process involves draining the fluid and removing the transmission pan to access the internal components.
5. Once the pan is off, inspect the internal wiring harness for damage.
6. Identify Shift Solenoid 'E' (SS-A). It is one of the two black, on/off type solenoids.
7. Test the resistance of shift solenoid 'E' with a multimeter. It should be between 10-11 Ohms. If the reading is open (infinite) or shorted (near zero), the solenoid is bad.
8. If the solenoid is out of spec, it is faulty and should be replaced. It is best practice to replace the entire 8-solenoid pack.
9. If the solenoid and wiring test good, the issue may be a clogged valve body passage 🎬 See how the A6GF1 valve body and solenoids function. or, in rare cases, the TCM.

Parts You'll Likely Need

• Automatic Transmission Solenoid Kit (8-Pack) (OEM #See description for kit contents) — This is the most common failure part for code P0773. Replacing the entire pack is the recommended repair to prevent future failures of other solenoids. The kit typically includes all 8 solenoids.
  Trusted brands: Genuine Kia/Hyundai, Mando, Shinghoi
  OEM price range: $350-$500 (kit)
  Aftermarket price range: $150-$300 (kit)
• Automatic Transmission Fluid (ATF) — The transmission fluid must be drained to access the solenoids and should be replaced with new fluid meeting the Kia SP-IV specification. Approximately 5-6 quarts are needed for a pan drop.
  Trusted brands: Genuine Kia/Hyundai SP-IV, Idemitsu TLS-LV, Valvoline MaxLife Multi-Vehicle ATF, AISIN ATF-SP4
  OEM price range: $15-$25 per quart
  Aftermarket price range: $8-$15 per quart
• Transmission Oil Pan Gasket (OEM #45285-3B810 (example, confirm with VIN)) — The gasket should be replaced whenever the oil pan is removed to ensure a proper seal and prevent leaks. Some technicians prefer using a high-quality RTV sealant specified for transmission fluid.
  Trusted brands: Genuine Kia, Fel-Pro, Mahle
  OEM price range: $20-$40
  Aftermarket price range: $10-$25

Related Codes That Often Appear With This One

• P0741, P0743, P0748, P0753, P0758, P0763, P0768, P1778, P2709 — These are all electrical fault codes for the torque converter clutch and other shift solenoids ('A', 'B', 'C', 'D', etc.). Kia groups them all together with P0773 in TSB TSBTRA051R1, indicating a common failure pattern for the solenoid assembly or internal harness in the A6GF1/A6MF1 transmission family.

Technical Service Bulletins (TSBs) & Recalls

• TSBTRA051R1: Provides information on replacing various shift solenoids on 6-speed automatic transaxles for a range of DTCs, including P0773, and advises against transaxle replacement. It covers a wide range of Hyundai and Kia vehicles.

Platform-Specific Known Issues

• Kia has issued Technical Service Bulletin #TSBTRA051R1, which covers the 2012-2015 Rio with the 6-speed automatic transmission. It acknowledges that codes like P0773 are likely caused by a faulty solenoid and explicitly states that the solenoid should be replaced, not the entire transaxle.
• The A6GF1 transmission in the Rio does not have a transmission fluid dipstick, making fluid level checks more involved than on older vehicles. The check/fill plug is located on the side of the transmission case.

Mechanic-Grade Diagnostic Values

• Automatic Transmission Fluid (ATF) Temperature for Level Check — expected: 122°F - 140°F (50°C - 60°C). Failure: N/A - This is the required temperature range to accurately check the fluid level via the side fill plug.

Scan Tool Commands That Help

• Kia GDS (Global Diagnostic System): Vehicle and A/T menu > Actuation Test — This dealer-level command directly tells the TCM to activate the solenoids. A 'Success' result means the command was sent, and a technician can listen for the solenoid click. A 'Failure' result indicates a communication breakdown, pointing the diagnosis toward the wiring or TCM before even opening the transmission.

Wiring & Ground Locations

• ECM Ground Pins — At the Engine Control Module (ECM) connector. For a 2014 Rio 1.4L, pins 3, 4, and 77 are listed as grounds.. A poor ground at the main computer can cause countless phantom electrical codes, including P0773. Verifying a solid ground is a key step before condemning expensive components.
• Chassis Ground Bolt — On the right side of the interior fuse panel (located below the steering wheel), there is often a silver bolt with multiple ground wires attached.. This is a primary grounding point for many interior electronics, potentially including the TCM or related circuits. Ensuring this connection is clean and tight can resolve intermittent electrical issues.

Real Owner Repair Stories

• YouTube channel 'Andy's Garage' (2013 Kia Rio) — Erratic shifting and transmission slipping, which are common symptoms associated with P0773.
  ❌ Tried (didn't work) The video is a 'how-to' on the correct fix, not a story of misdiagnosis.
  ✅ What actually fixed it The video demonstrates the process of removing the transmission valve body to access and replace the shift solenoids. The mechanic shows that the solenoids are held by a bracket secured with H5 (5mm) hex bolts. The fix is to remove the bracket and pull out the individual solenoids for replacement or cleaning.

OEM Part Supersession History

• 46313-3B020 → 46313-3B030 — Unknown, but part revisions are often made to improve reliability and address known failure points.
  Heads up: The new part number (46313-3B030) is the correct replacement for the original. Using old stock of the -3B020 part is not recommended.

Model Year Variations Within This Range

• 2015: The 2015 model year received a cosmetic facelift. While the underlying A6GF1 transmission and its solenoids remained the same, technicians should be aware of potential minor differences in body panels or brackets when accessing the transmission compared to 2012-2014 models. The core cause and fix for P0773 are identical.