P1931 Code - Fuel Additive Pump Control Circuit/Open
Quick Answer
The Fuel Additive Pump is a positive displacement pump (reciprocating pump) and, in response to commands from the fuel additive control unit, delivers a metered quantity of fuel additive to the injector on the top of the fuel tank via a short fuel pipe; the injector then injects the additive into the fuel tank. Common causes include Faulty Fuel Additive Level Pump, Fuel Additive Level Pump harness is open or shorted, Fuel Additive Level Pump 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
- P1931 indicates Fuel Additive Pump Control Circuit/Open.
- Common causes
- Common causes include Faulty Fuel Additive Level Pump, Fuel Additive Level Pump harness is open or shorted, Fuel Additive Level Pump 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 P1931 Description
The piezo sensor on the Fuel Additive Pump records the fill level of the fuel additive in the fuel additive tank and transmits this information to the fuel additive control unit.
Its other task is to determine any change in the viscosity of the fuel additive as a function of ambient temperatures; this may result in the metered quantity of fuel additive having to be corrected.
If the fill level of the fuel additive in the fuel additive tank falls below a certain limit, the engine system fault warning lamp in the instrument cluster will switch on.
If the fuel additive tank becomes empty, the Malfunction Indicator Lamp (MIL) will light up.
What are the Possible Causes of the DTC P1931?
- Faulty Fuel Additive Level Pump
- Fuel Additive Level Pump harness is open or shorted
- Fuel Additive Level Pump circuit poor electrical connection
How to Fix the DTC P1931?
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 P1931 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.
Need more information about the P1931 code?
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Information for Specific Makes
- P1931 Ford — Fuel Additive Pump Control Circuit/Open
- P1931 Lincoln — Fuel Additive Pump Control Circuit/Open
- P1931 Mazda — Fuel Additive Pump Control Circuit/Open
- P1931 Mercury — Fuel Additive Pump Control Circuit/Open
Frequently Asked Questions about P1931 Code
1. What are common symptoms of OBDII code P1931 (Fuel Additive Pump Control Circuit/Open)?
- Common symptoms include poor engine performance, rough idling, decreased fuel efficiency, and the illumination of the Check Engine Light.
2. What can cause OBDII code P1931 to trigger?
- Code P1931 is typically triggered by a malfunction in the fuel additive pump control circuit, such as a damaged wiring harness, faulty fuel pump relay, or a defective fuel additive pump.
3. How serious is OBDII code P1931 (Fuel Additive Pump Control Circuit/Open)?
- While the vehicle may still be operable with this code present, it is important to address it promptly to prevent potential damage to the fuel system and ensure optimal engine performance.
4. How can I diagnose the cause of OBDII code P1931?
- Diagnosing code P1931 often involves checking the wiring harness for any damage, testing the fuel pump relay for proper function, and inspecting the fuel additive pump for any defects.
5. What are some repair tips for addressing OBDII code P1931?
- Repair tips may include repairing or replacing damaged wiring, testing and replacing a faulty fuel pump relay, or replacing the fuel additive pump if it is found to be defective.
6. Can I drive my vehicle with OBDII code P1931 present?
- It is generally not recommended to drive the vehicle with this code present, as it can lead to decreased fuel efficiency and potential engine performance issues.
7. How much does it typically cost to repair OBDII code P1931?
- The cost of repairing code P1931 can vary depending on the specific cause of the issue, but it may range from $100 to $500 or more, including parts and labor.
8. Is it possible to reset OBDII code P1931 without repairs?
- While clearing the code may temporarily turn off the Check Engine Light, the underlying issue causing code P1931 will still need to be addressed to prevent further problems.
9. Can a DIY enthusiast repair OBDII code P1931 at home?
- Depending on the cause of the code, DIY enthusiasts with automotive repair experience may be able to address code P1931 at home by following repair guides and using the necessary tools.
10. How long does it take to repair OBDII code P1931?
- The repair time for code P1931 can vary based on the specific cause and complexity of the repair, but it may take anywhere from 1 to 4 hours or more to complete the necessary repairs.
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