P0606 on Citroen: How to Diagnose & Fix
PCM Processor Fault
1 Citroen model · 1 documented issue · 1 critical · $300-$900 repair
P0606 on Citroen by model: symptoms, diagnosis and fix
The C3 Mark I and II experience electric power steering failures caused by the column-mounted EPS motor and its control ECU. The steering becomes heavy without warning, which is particularly dangerous at low speeds during parking.
Common Symptoms
- Sudden heavy steering
- Power steering warning light
- Intermittent assist loss
- Steering column noise
How to Fix
Replace the EPS motor and control unit assembly. Some specialist repairers can refurbish the ECU by resoldering cracked joints. Check for a Citroën recall on your VIN.
P0606 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0606 mean on a Citroen?
P0606 stands for "PCM Processor Fault." P0606 indicates an internal processor or performance fault within the powertrain control module (PCM) — essentially the engine's main computer has detected that one of its own internal circuits or processors is not functioning correctly. Because the PCM controls fuel, ignition, and many other functions, an internal fault can affect almost any aspect of engine operation. Symptoms range from no obvious effect to stalling, no-start, erratic running, or multiple unrelated trouble codes appearing together. This often points to the module itself, though power and ground supply issues can mimic it. On Citroen it is documented across 1 model: C3.
What are the most common causes of P0606?
The most common causes of P0606 are: Poor power or ground supply to the PCM, Corroded, loose, or damaged PCM connectors, Low system/battery voltage or charging system fault, Water intrusion or corrosion at the module, Internal PCM hardware/processor failure, Failed or corrupted PCM software needing reflash, Wiring damage affecting the PCM power/ground circuits. The specific cause varies by vehicle.
How much does it cost to fix P0606 on a Citroen?
Published repair estimates on Citroen range from $300 to $900 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.