P1933 Code - Fuel Additive Pump Control Circuit Low
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
- P1933 indicates Fuel Additive Pump Control Circuit Low.
- 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 P1933 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 P1933?
- 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 P1933?
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 P1933 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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Information for Specific Makes
- P1933 Ford — Fuel Additive Pump Control Circuit Low
- P1933 Lincoln — Fuel Additive Pump Control Circuit Low
- P1933 Mazda — Fuel Additive Pump Control Circuit Low
Frequently Asked Questions about P1933 Code
1. What does OBDII code P1933 mean?
P1933 indicates a low voltage issue in the fuel additive pump control circuit, which is responsible for managing the diesel exhaust fluid or fuel additive system.
2. What are common symptoms of code P1933?
Symptoms include an illuminated check engine light, poor exhaust system performance, reduced fuel efficiency, and possible issues with emissions compliance.
3. What causes code P1933?
Common causes include a faulty fuel additive pump, damaged wiring or connectors, a blown fuse, or issues with the power supply to the pump.
4. Can I drive with code P1933?
Driving with this code may lead to increased emissions or reduced engine performance, but it is generally not an immediate safety concern. Prompt repair is recommended.
5. How do I diagnose code P1933?
Diagnosis involves inspecting the wiring and connectors, testing the fuel additive pump, checking fuses, and verifying the voltage levels in the control circuit.
6. How can I fix code P1933?
Repairs may include replacing the fuel additive pump, repairing damaged wiring, replacing blown fuses, or addressing electrical issues in the control circuit.
7. What tools do I need to diagnose code P1933?
You'll need a scan tool, a multimeter for testing voltage, and potentially wiring diagrams for the fuel additive system.
8. Is code P1933 specific to certain vehicles?
Yes, P1933 is typically seen in diesel vehicles equipped with a fuel additive system, such as those that use diesel exhaust fluid (DEF).
9. Can a fuel additive pump failure trigger code P1933?
Yes, a malfunctioning or failed fuel additive pump is one of the main causes of this code.
10. How much does it cost to repair code P1933?
Repair costs vary depending on the issue, but replacing a fuel additive pump can range from $300 to $800, excluding labor.
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