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DTC codes / P26xx · Computer and output circuits / P260E

P260EParticulate Filter Regeneration Lamp Control Circuit

P260E indicates that the powertrain control module has detected a fault in the electrical circuit that controls the particulate filter regeneration lamp, which is the dashboard indicator that tells the driver a diesel particulate filter regeneration is underway or required. The computer monitors the lamp control circuit for expected voltage or current behavior and sets this code when the circuit does not respond as commanded, often due to an open, short, or excessive resistance in the wiring or lamp assembly.

SystemPowertrain
Code typeGeneric (all makes)
SeverityLow
Fix difficultyIntermediate
AreaComputer and output circuits

Symptoms you may notice

  • The particulate filter regeneration lamp may fail to illuminate when the computer commands a regeneration, leaving the driver unaware of the filter's status.
  • The lamp may stay illuminated continuously even when no regeneration is active, confusing the driver about the filter's condition.
  • A stored trouble code will illuminate the check engine light or a dedicated emissions warning lamp on the dashboard.
  • In some vehicles, the regeneration process may be inhibited as a safety measure, leading to reduced engine performance or limited vehicle speed.
  • Often no symptoms besides the warning light, with the vehicle driving normally and regeneration occurring without the driver's knowledge.

Common causes, most likely first

  1. A burned-out or damaged particulate filter regeneration lamp bulb or LED assembly.
  2. Corroded, loose, or disconnected electrical connector at the lamp, the instrument cluster, or the control module.
  3. An open circuit in the power or ground wire between the control module and the lamp, often due to a broken wire or chafed insulation.
  4. A short to ground or short to voltage in the lamp control circuit, which can be caused by pinched wiring or moisture intrusion.
  5. A failed instrument cluster or body control module that cannot properly drive the lamp circuit.
  6. A faulty powertrain control module driver circuit, though this is less common and should be confirmed after all other possibilities are ruled out.
  7. Aftermarket accessories or improper wiring repairs that have tapped into the lamp circuit and altered its resistance.

How to diagnose and fix it

  1. Verify the complaint and check for any related technical service bulletins or recalls that might address the lamp circuit.
  2. Inspect the regeneration lamp bulb or LED and replace it if it is visibly burned out or damaged.
  3. Disconnect and inspect the electrical connectors at the lamp, instrument cluster, and control module for corrosion, loose pins, or water intrusion, cleaning or repairing as needed.
  4. Use a digital multimeter to check for continuity and resistance in the lamp control circuit between the control module and the lamp, looking for opens or excessive resistance.
  5. Check for shorts to ground or shorts to voltage on the control circuit with the ignition on and the lamp commanded off, repairing any damaged wiring.
  6. If the circuit tests good, use a scan tool to command the lamp on and off while monitoring the control module's output, and if the module does not respond, diagnose the module or cluster as faulty.
  7. Clear the diagnostic trouble codes and perform a road test to verify the regeneration lamp operates correctly and the code does not return.

What the regeneration lamp circuit really tells you

  • A common oversight is assuming the lamp itself is faulty when the real problem is a poor ground connection at the instrument cluster, which can affect multiple lamps and gauges simultaneously.
  • Some vehicles use the same lamp for both regeneration active and filter full warnings, so a circuit fault can mask a genuinely needed regeneration and lead to filter damage if ignored.
  • The code can be set by a brief intermittent open circuit that only occurs during vibration or temperature changes, so a wiggle test of the harness while monitoring the lamp is often necessary.
  • Aftermarket remote starters or alarm systems that tap into the instrument cluster wiring are a frequent cause of unexplained lamp circuit faults.
  • Do not replace the powertrain control module based solely on this code; the module's driver circuit is rarely the culprit, and a thorough circuit test should always precede module replacement.

Can I keep driving with P260E?

The vehicle is generally safe to drive because the fault only affects the regeneration indicator lamp, but you should avoid long periods of stop-and-go driving or heavy loads until the lamp is repaired, as you may not receive warning when a regeneration is needed. If the check engine light is flashing or performance is reduced, have the vehicle inspected promptly.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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