What Does P099E Mean?
The TCM has detected that the shift solenoid 'H' control circuit is reading low, indicating a short to ground in the solenoid or its wiring. The TCM cannot properly modulate solenoid H current, which disrupts the hydraulic control of the associated clutch pack or band in the transmission.
Common Causes
35%
Shift solenoid H internally shorted to ground
30%
Wiring harness short to ground in solenoid H circuit
20%
Corroded transmission case connector causing low-resistance path to ground
15%
TCM driver circuit failure pulling the line low
Diagnostic Steps
1
Step 1: Disconnect the transmission case connector and measure solenoid H resistance. Values well below specification confirm an internal coil short.
2
Step 2: With the transmission connector unplugged, check for continuity from the solenoid H control wire to ground on the harness (TCM) side. Any reading indicates a wiring short.
3
Step 3: Inspect the transmission internal harness for chafing, melting, or pinch points. Pay attention to routing near the valve body and case edges.
4
Step 4: Check the transmission case connector for ATF contamination, corrosion, or water intrusion that could create unintended ground paths.
5
Step 5: If external circuits are clean, test TCM solenoid H driver output with the harness disconnected. A stuck-low output points to a TCM failure.
Estimated Repair Cost
$200 - $850
Parts + labor, varies by vehicle and location
The TCM has detected that the shift solenoid 'H' control circuit is reading low, indicating a short to ground in the solenoid or its wiring. The TCM cannot properly modulate solenoid H current, which disrupts the hydraulic control of the associated clutch pack or band in the transmission.
The most common cause of P099E (Shift Solenoid "H" Control Circuit Low) is: Shift solenoid H internally shorted to ground
Typical repair costs for P099E range from $200 to $850, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Transmission may default to limp mode. Affected gear ratios will not be available. Limit driving to reach a repair facility.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P099E to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Powertrain
System
Transmission Shift Control
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
