Code P1043 Audi: Injector 3 Supply Voltage Short Circuit
1. Definition
- Generic Meaning:
Code P1043 indicates a short circuit in the supply voltage circuit for injector #3. - Audi Specifics:
Audi may use a different description for this code depending on the model and year. Consult Audi technical manuals or a specialized diagnostic tool for more details.
2. Common Symptoms
- 🚨 Check Engine Light On (or “Service Engine Soon” message).
- 🛑 Performance Issues:
- Misfire on cylinder 3.
- Unstable idle or stalling.
- Loss of power or hesitant acceleration.
- ⚡ Abnormal Fuel Consumption.
3. Possible Causes
- Faulty Injector:
- Internal failure of injector #3 (coil or internal circuit).
- Electrical Problems:
- Injector #3 wiring harness open, shorted, or damaged.
- Injector connector corroded, loose, or with bent/broken pins.
- Other Causes:
- Engine Control Module (ECU) failure in rare cases.
4. Diagnostic Procedures
Preliminary Steps
- Check for Related Codes:
- Use an OBD-II scanner to identify other stored codes (e.g., P0203, P0263).
- Visual Inspection:
- Inspect the #3 injector wiring harness, connector, and adjacent components for:
- Exposed wires, chafing, or burns.
- Corrosion, oxidation, or damaged pins.
Electrical Tests
- Continuity Test:
- Use a multimeter to check for no breaks in the injector circuit.
- Injector Resistance Test:
- Disconnect the injector and measure its resistance (compare with Audi specifications, typically between 12-18 Ω).
- Voltage Test:
- Check the supply voltage (12V) with the key in the “ON” position.
Swap Test
- Swap injector #3 with another cylinder:
- If the code moves (e.g., to P1044), the injector is faulty.
5. Recommended Repair
- Replace injector #3:
- If the injector is faulty, use an OEM or equivalent quality part.
- Repair the wiring/connector:
- Solder/replace damaged wires.
- Clean contacts with electrical contact cleaner or replace the connector.
- Reset the code:
- Clear the code with a scanner and perform a road test to confirm the repair.
6. Mistakes to Avoid
- Ignoring related codes: A P0641 code (5V supply issue) could mask the real cause.
- Neglecting grounding: Check the engine and ECU ground connections.
- Forgetting reprogramming: Some Audi models require ECU adaptation after injector replacement.
7. Recommended Tools
- Audi-compatible OBD-II scanner (e.g., VCDS, ODIS).
- Digital multimeter.
- Oscilloscope (for analyzing injector signal).
In summary: Code P1043 on an Audi points to an electrical or mechanical problem with injector #3. A methodical approach (inspection, electrical tests, swapping) helps identify the exact cause. If in doubt, consult Audi TSBs or a certified specialist.