Owners Skoda Octavia A5 (2004–2013) often encounter an annoying problem: the on-board computer constantly polls the performance of the lamps, even if they are working. This leads to false errors on the dashboard, blinking indicators and incorrect operation of the lighting system. The problem is especially acute after replacing lamps with LED ones or installing non-standard ignition units.

The reason lies in the architecture CAN buses and diagnostic protocols Octavia A5: controllers 09 Centr. Electr. and 05 Acc/Start Auth. actively monitor the resistance of the lamp circuits. If it does not correspond to the factory parameters (for example, LED lamps have lower resistance), the system detects a β€œbreak”. In this article we will analyze all working methods for disabling polling - from software coding to hardware solutions - as well as the risks and consequences of each method.

Why does a lamp polling error occur and when should it be turned off?

Lamp polling system Octavia A5 laid down at the controller firmware level. Its main task is to prevent driving with faulty lighting, which is critical for safety. However, in real operation this often leads to false positives. Typical scenarios:

  • πŸ”§ Installation LED lamps instead of halogen ones (the circuit resistance drops from ~3–5 Ohms to ~0.5–1 Ohms).
  • πŸ’‘ Replacing xenon ignition units with non-original ones (there is no feedback via the CAN bus).
  • πŸ”Œ Short circuit or open circuit (for example, after wiring repair).
  • πŸš— Connecting additional equipment (fog lights, daytime running lights) without adjusting the firmware.

It is advisable to disable the survey only in two cases:

  1. You are confident that all lamps and circuits are working properly, but the error appears due to equipment incompatibility.
  2. Are you planning constantly use LED lighting, and false positives interfere with operation.
⚠️ Attention: Disabling lamp polling deprives you of protection from real lighting faults. For example, if a brake light burns out, you will not know about it until an inspection or an accident occurs. In some countries (for example, Germany, Austria), driving with lamp diagnostics disabled may result in a fine during a technical inspection.

Method 1: Disable polling via VCDS (VAG-COM)

The most reliable and reversible method is controller coding 09 Centr. Electr. using a diagnostic scanner VCDS (or analogues like OBDeleven, Carista). You will need a laptop with the program, an adapter and basic skills in working with diagnostic software.

Step by step instructions:

  1. Connect VCDS to the diagnostic connector OBD-II (located under the steering wheel, to the left of the brake pedal).
  2. Launch the program, select the model Skoda Octavia (1Z) and the engine of your modification.
  3. Go to block 09 β€” Centr. Electr. (Central Electronics).
  4. Click Coding - 07 β†’ Long Coding Helper.
  5. In the window that opens, find the byte responsible for polling the lamps. For Octavia A5 this is usually byte 18 (may vary depending on the year and configuration!).
  6. Uncheck the box LeuchtmittelΓΌberwachung aktiv (or similar, depending on the software version).
  7. Save the changes and reboot the controller (turn off/start the car).

If the error remains after coding, check:

  • πŸ”Ή Correct byte selection (in some firmware, lamp polling is embedded in the byte 19 or 20).
  • πŸ”Ή Controller firmware version (update it if necessary).
  • πŸ”Ή Availability of additional modules (for example, 46 β€” Comfort System), which can also poll lamps.

Download the latest version of VCDS (at least 22.10)|Check the battery voltage (minimum 12.4 V)|Disable all consumers (headlights, radio, climate control)|Prepare a backup copy of the current encoding (Save Coding)

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For models with xenon headlights may require additional disabling of polling in the block 55 β€” Headlight Range (adjusting headlights). In this case:

Addressing: 55 β†’ Adaptation - 10 β†’ Channel "Lamp Monitoring" β†’ Value "0" (off)

Method 2: Hardware shutdown (resistors and snags)

If software disabling did not help or you do not have access to VCDS, you can follow this path hardware emulation. The essence of the method is to β€œdeceive” the system by simulating the standard resistance of the circuit. This is true for LED lamps and non-original ignition units.

Implementation options:

Method Application Pros Cons
Resistors in a circuit For LED lamps in dimensions, brake lights Cheap (50–200 rubles), easy to install Heating of resistors, risk of wiring melting
CAN bus decoys For xenon, fog lights Full emulation of the standard signal Expensive (1500–3000 rubles), difficult installation
Diode bridges For daytime running lights (DRL) Minimal voltage loss Requires soldering work

An example of a circuit for side lights with LED lamps:

Connect a resistor in parallel with the lamp 6.8 Ohm 50W (to simulate a halogen lamp). Important:

  • πŸ”₯ Use ceramic resistors (they heat up less).
  • πŸ”§ Mount the resistor on a heat sink or away from plastic parts.
  • πŸ“ The length of the wires from the resistor to the lamp is no more than 10 cm.
⚠️ Attention: Incorrectly selected resistance or power of the resistor can lead to circuit overload and wiring fire. For example, a 3 Ohm resistor on dimensions will consume ~1.5 A, which is close to the limit for standard wiring Octavia A5.
How to calculate the resistance of a resistor?

Formula: R = UΒ² / P, where:

- U β€” on-board network voltage (12–14 V),

- P - power of a standard lamp (for example, 5 W for dimensions).

For a 5 W lamp: R = 14Β² / 5 β‰ˆ 39.2 Ohm. In practice, they take the nearest standard value (39 Ohms) with a power reserve (10–20 W).

Method 3: Updating the controller firmware

In some cases, lamp polling can be disabled, by updating the unit's firmware 09 Centr. Electr. to a newer version. This is relevant for early Octavia A5 (2004–2007), where lamp diagnostics were less "smart".

Algorithm of actions:

  1. Download the latest firmware for your controller (for example, from the forum Ross-Tech or SkodaClub).
  2. Make a backup of the current firmware via VCDS or ODIS.
  3. Upload new firmware using Flash Tool (included with VCDS).
  4. Reset adaptations (Basic Settings - 04 β†’ Reset).

Advantages of the method:

  • πŸ”„ Ability to return old firmware if unsuccessful.
  • πŸš€ Often solves the polling problem without additional coding.

Risks:

  • ⚑ If you interrupt the firmware process, the controller may fail.
  • πŸ”§ Not all firmware is compatible with your modification Octavia A5.
πŸ’‘

Before flashing, turn off all consumers and connect the car to the charger. A voltage drop below 11.8 V during the process can β€œkill” the controller.

Method 4: Alternative solutions (without interfering with the electrical system)

If you don't want to risk flashing firmware or a soldering iron, consider workarounds:

  • πŸ”„ Reset errors via VCDS or ELM327 scanner (temporary solution, the error will return after the next polling cycle).
  • πŸ’‘ Using lamps with built-in decoys (for example, LED lamps Osram LEDriving or Philips X-tremeVision with resistors in the base).
  • πŸ“± Mobile applications type Torque Pro for manual error reset (requires Bluetooth OBD-II adapter).

For owners Octavia A5 with xenon headlights there is another trick: disabling polling via Adaptation in the block 55 β€” Headlight Range. To do this:

Addressing: 55 β†’ Adaptation - 10 β†’ Channel "Lamp Diagnosis" β†’ Value "not active"

Software coding (VCDS)|Installing resistors/switches|Updating firmware|I use lamps with tricks|I don’t turn it off, I drive with an error

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Common mistakes and how to avoid them

When turning off lamp polling, many people make critical mistakes that lead to new problems. Let's look at the most common ones:

Error Consequences How to avoid
Incorrect byte in encoding Disabling other functions (eg central locking) Check the description of each bit in Long Coding Helper
Using underpowered resistors Overheating, wiring melting, short circuit Take resistors with power reserve (minimum 20 W)
Firmware of incompatible software version Inoperative functions (window lifters, climate control) Use firmware only for your VIN and year of manufacture

Another typical problem is error U112100 (No Communication with Light Switch) after polling is turned off. It occurs if the controller 09 stops β€œseeing” the light switch. Solution:

  1. Check the fuse F41 (10 A) in the fuse box.
  2. Reset adaptations in block 09 (Basic Settings - 04 β†’ Group 001).
  3. If the error remains, return the factory coding and repeat the procedure.
πŸ’‘

Before any manipulations with coding or firmware be sure to save your current controller settings. This will allow you to return everything back in case of failure.

FAQ: Answers to frequently asked questions

Is it possible to disable polling of lamps without VCDS?

Yes, but with restrictions. Alternatives:

  • πŸ“± Applications like OBDeleven or Carista (functionality is reduced, but enough for basic coding).
  • πŸ”§ Hardware decoys (resistors, CAN filters).
  • πŸ”„ Manual error reset via ELM327 scanner (temporary solution).

However, to completely disable polling VCDS is recommended β€” it gives access to all bytes of the encoding.

Will the error light on the panel remain on after polling is disabled?

If you have disabled polling correctly and cleared errors, the indicator will turn off. However:

  • πŸ”Ή With the hardware method (resistors), an error may appear when real malfunction lamps
  • πŸ”Ή If the error remains after encoding, check other blocks (for example, 46 β€” Comfort System).
Does disabling polling affect the operation of other systems?

In most cases, no. However:

  • πŸš— On some Octavia A5 with automatic light (Light Assist) disabling polling may lead to incorrect operation of the light sensor.
  • πŸ”‹ If you have updated the controller firmware, check the operation window lifters and central lock - they sometimes β€œfly off”.
Is it possible to disable polling only for certain lamps (for example, only for dimensions)?

Yes, but it requires dot coding. In the block 09 Centr. Electr. Each type of lamp (dimensions, brake lights, PTF) can have a separate polling bit. For example:

  • πŸ”¦ Dimensions: bit 3 in byte 18.
  • 🚦 Stop lights: bit 5 in byte 19.
  • πŸ’‘ Fog lights: bit 1 in byte 20.

Find the exact bit map in encoding manuals for your firmware version.

What should I do if, after disabling polling, some functions stop working?

Reset the factory coding and check:

  1. Have you touched other bits in the byte (for example, those responsible for interior lighting or beep).
  2. Is the controller firmware compatible with your configuration? Octavia A5.
  3. Are there any errors in other blocks (check 17 β€” Instruments and 19 β€” CAN Gateway).

If the problem persists, contact a specialist VCDS for diagnostics.