P171D GMC Code - Transmission Fluid Pressure Accumulator System Performance
Quick Answer
The Automatic Transmission Auxiliary Fluid Accumulator is used to provide transmission fluid line pressure to the transmission during an autostart event. Common causes include Faulty Transmission Fluid Pressure Accumulator, Transmission Fluid Pressure Accumulator harness is open or shorted, Transmission Fluid Pressure Accumulator circuit poor electrical connection. 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
- P171D GMC indicates Transmission Fluid Pressure Accumulator System Performance.
- Common causes
- Common causes include Faulty Transmission Fluid Pressure Accumulator, Transmission Fluid Pressure Accumulator harness is open or shorted, Transmission Fluid Pressure Accumulator circuit poor electrical connection.
- 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 P171D GMC Description
When the engine is shut off during an autostop event, there is no transmission line pressure. During an autostart event, the Hybrid/EV Powertrain Control Module 1 commands the Automatic Transmission Auxiliary Fluid Accumulator solenoid valve on, allowing transmission fluid to discharge from the accumulator, supplying line pressure to the transmission. The accumulator will start to recharge when the transmission fluid pump increases line pressure higher than accumulator pressure. Transmission fluid will flow through the solenoid valve until the Hybrid/EV Powertrain Control Module 1 turns the solenoid off and also flow through a check valve.
The Hybrid/EV Powertrain Control Module 1 monitors clutch slip during an autostart event. The DTC will set if the Hybrid/EV Powertrain Control Module 1 detects that the accumulator system is not capable of supplying adequate pressure during autostart.
Hybrid/EV Powertrain Control Module 1 detects excessive transmission slip during an autostart. This must occur 15 times, with 3 of the times on separate autostart events.
What are the Possible Causes of the DTC P171D GMC?
- Faulty Transmission Fluid Pressure Accumulator
- Transmission Fluid Pressure Accumulator harness is open or shorted
- Transmission Fluid Pressure Accumulator circuit poor electrical connection
How to Fix the DTC P171D GMC?
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.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P171D GMC 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 P171D GMC Code
1. What are the common symptoms of OBDII code P171D GMC (Transmission Fluid Pressure Accumulator System Performance)?
- Common symptoms include rough shifting, delayed gear engagement, transmission slipping, and illuminated warning lights on the dashboard.
2. What are the possible causes of OBDII code P171D GMC?
- Possible causes can include low transmission fluid levels, a faulty transmission pressure control solenoid, a clogged transmission filter, or issues with the transmission pump.
3. How can I diagnose OBDII code P171D GMC?
- Diagnosis typically involves using a scan tool to retrieve the code, checking transmission fluid levels and condition, inspecting for leaks, and testing the pressure control solenoid and accumulator for proper operation.
4. Can driving with OBDII code P171D GMC cause further damage to the vehicle?
- Continuing to drive with this code may lead to further damage to the transmission, potentially resulting in more severe issues and costly repairs.
5. What are some repair tips for fixing OBDII code P171D GMC?
- Repair tips may include checking and topping up transmission fluid, replacing the transmission filter, cleaning or replacing the pressure control solenoid, and inspecting the accumulator for any faults.
6. Is it safe to continue driving my vehicle with OBDII code P171D GMC?
- It is not recommended to continue driving your vehicle with this code, as it can lead to performance issues and potential damage to the transmission.
7. How much does it typically cost to repair OBDII code P171D GMC?
- The cost of repairs can vary depending on the underlying issue, but it may range from a few hundred to over a thousand dollars, including parts and labor.
8. Can I reset OBDII code P171D GMC on my own?
- While you can clear the code with a scan tool, it is important to address the underlying issue causing the code to prevent it from reoccurring.
9. Will OBDII code P171D GMC cause my vehicle to fail an emissions test?
- Yes, having this code stored in the vehicle's system may cause it to fail an emissions test, as it indicates a potential issue with the transmission.
10. How can I prevent OBDII code P171D GMC from occurring in the future?
- Regular maintenance, such as checking and changing transmission fluid as recommended, can help prevent issues that may trigger this code.
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