P0732 2018 GMC Sierra Code - Transmission 2nd Gear Ratio Incorrect
Quick Answer
The transmission turbine speed sensor and vehicle speed sensor are hall-effect sensors. Common causes include Low transmission fluid level, Shift solenoid mechanical fault, Faulty Turbine Sensor. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P0732 2018 GMC Sierra indicates Transmission 2nd Gear Ratio Incorrect.
- Common causes
- Common causes include Low transmission fluid level, Shift solenoid mechanical fault, Faulty Turbine Sensor.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P0732 2018 GMC Sierra Description
The TCM provides a 9 V reference circuit and a signal circuit to each of the sensors. As the 1-2-3-4-5-6 clutch piston housing and transmission output shaft or transfer case output rotates, the sensors produce a signal frequency based on the teeth on the reluctor wheel. The TCM calculates the transmission gear ratio based on the speed sensor signals and compares the calculated gear ratio to the commanded gear ratio.
The Diagnostic Trouble Code (DTC) will be set when the TCM detects the calculated gear ratio with 2nd gear commanded differs from the known 6th gear ratio for 2 s.
What are the Possible Causes of the DTC P0732 2018 GMC Sierra?
- Low transmission fluid level
- Shift solenoid mechanical fault
- Faulty Turbine Sensor
- Faulty Output Speed Sensor
How to Fix the DTC P0732 2018 GMC Sierra?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
Code Tech Notes
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0732 2018 GMC Sierra code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Frequently Asked Questions about P0732 2018 GMC Sierra Code
What does the OBDII code P0732 mean for a 2018 GMC Sierra?
P0732 indicates that the Powertrain Control Module (PCM) has detected an incorrect gear ratio in the transmission when the vehicle is in 2nd gear.
What are the common symptoms of code P0732 in a 2018 GMC Sierra?
Symptoms include harsh shifting, slipping in 2nd gear, reduced fuel efficiency, transmission overheating, and the illumination of the check engine light.
What causes the P0732 code to appear in a 2018 GMC Sierra?
Common causes include low transmission fluid, worn clutch packs, a faulty shift solenoid, a damaged valve body, or issues with the transmission control module (TCM).
How can I diagnose the P0732 code in my 2018 GMC Sierra?
Start by checking the transmission fluid level and condition. Use a diagnostic scanner to check for additional transmission-related codes and inspect components like solenoids, sensors, and wiring for damage.
Can I drive my 2018 GMC Sierra with the P0732 code?
Driving with this code is not recommended, as it can cause further damage to the transmission and negatively impact vehicle performance.
How do I fix the P0732 code in a 2018 GMC Sierra?
Repairs may include topping off or replacing the transmission fluid, replacing a faulty shift solenoid, repairing damaged wiring, or rebuilding the transmission if internal components are worn.
How much does it cost to repair a P0732 code on a 2018 GMC Sierra?
Repair costs can range from $100 for fluid replacement to several thousand dollars for a full transmission rebuild, depending on the root cause.
Can low transmission fluid cause a P0732 code?
Yes, low or degraded transmission fluid can cause a P0732 code because it affects the transmission's ability to maintain proper hydraulic pressure.
What tools are needed to troubleshoot a P0732 code in a 2018 GMC Sierra?
You’ll need an OBDII scanner, a transmission fluid dipstick or inspection tool, basic hand tools, and possibly a multimeter for electrical diagnostics.
Can a faulty transmission control module (TCM) trigger the P0732 code?
Yes, a malfunctioning TCM can fail to properly manage gear ratios, leading to the P0732 code being stored.
Discuss the causes and fixes for P0732 2018 GMC Sierra OBDII Code
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