Fix P099B: STEP-BY-STEP diagnostic GUIDE!

The P099B: Shift Solenoid ‘G’ Control Circuit Low refers to a low voltage issue in the control circuit of shift solenoid ‘G’. This can be due to a faulty solenoid, low voltage supply, or wiring/connector issues that can result in improper gear shifting or transmission malfunctions.

P099B – Quick Overview

Code	Information
Meaning	P099B: Shift Solenoid ‘G’ Control Circuit Low
Is it serious?	Yes, this code can lead to improper shifting or transmission failure.
Possible causes	– Low voltage in the shift solenoid ‘G’ control circuit – Faulty shift solenoid ‘G’ – Wiring or connector issues
How to diagnose?	– Check the circuit for low voltage – Inspect wiring and connectors – Replace the shift solenoid ‘G’ if necessary

P099B Meaning

The P099B code indicates that the shift solenoid ‘G’ is receiving a lower voltage than expected. This could result in problems with gear shifting and overall transmission operation. The root cause might be a faulty solenoid or issues in the wiring or connectors leading to the solenoid.

Step-by-step diagnostic guide

Action	Description	Tools Needed
Check for Other Codes	Use an OBD-II scanner to check if there are additional transmission or solenoid-related codes.	OBD-II Scanner
Inspect Shift Solenoid ‘G’	Visually inspect shift solenoid ‘G’ for any signs of physical damage.	Flashlight, Safety Gloves
Test the Circuit for Low Voltage	Use a multimeter to test the voltage in the shift solenoid ‘G’ control circuit.	Multimeter
Inspect Wiring and Connectors	Examine the wiring and connectors for any shorts, corrosion, or breaks.	Flashlight, Multimeter
Replace Shift Solenoid ‘G’	If necessary, replace the faulty shift solenoid ‘G’.	Replacement Parts (Solenoid)
Clear the Code and Test Drive	After repairs, clear the code using an OBD-II scanner and perform a test drive.	OBD-II Scanner, Vehicle Manual
Recheck for Codes	Re-scan the vehicle to ensure the P099B code has not returned.	OBD-II Scanner