Generic OBD2 code · Powertrain

P0606 ECM/PCM Processor

P0606 is a generic OBD2 powertrain code. It means “ECM/PCM Processor” — the same on every make and model, because the definition comes from the SAE J2012 standard rather than from the carmaker.

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System
Powertrain (P)
Code type
Generic (SAE)
Range
P06xx
Urgency
High

What P0606 means

The engine computer runs self-tests on its own memory and processor, and one failed: a processor fault (P0606), a memory checksum error (P0601) or a read-only memory error (P0605).

Symptoms

  • Sometimes nothing but the lamp
  • Stalling, a no-start or limp mode
  • Several unrelated codes, or erratic behavior

Most likely causes

  1. Low or unstable supply voltage and poor grounds
  2. Software that needs updating — many makers publish fixes for these codes
  3. Water damage or corrosion at the module or its connectors
  4. A failed control module

What to check first

  1. Check the battery voltage, the terminals and the engine grounds
  2. Ask a dealer whether there is a software update for your car
  3. Replace or repair the module only after power, grounds and software are ruled out — a new one usually has to be programmed to the car

Can I keep driving with P0606?

Limit driving — get it checked promptly

With caution. If the car runs normally, get it checked soon; if it stalls or goes into limp mode, don’t rely on it.

How P0606 breaks down

P
System

Powertrain. Engine, transmission, fuel and emissions — the codes behind the check engine lamp.

0
Standard

Generic code: defined by SAE, the same on every make.

6
Subsystem

Computer & output circuits.

06
Fault

The specific fault within this range.

P0606: a powertrain code, generic, in the computer & output circuits range, fault 06.

Where to look: Computer & output circuits

The control modules themselves and the circuits they drive: internal memory and processor self-tests, sensor reference voltages, glow plugs, coolant pumps, relays and other outputs.

All P06xx codes →

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Read and clear P0606 on your iPhone

Brimly reads stored, pending and permanent codes through a Bluetooth LE or Wi-Fi OBD2 adapter, explains each one offline from the same 2,693-code dictionary as this page, and clears them once the fault is fixed — each clear goes into the car’s service history with the codes it removed. OBD diagnostics are part of Brimly Forever, a one-time purchase; the PRO assistant explains a code for your exact car.

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Frequently asked

What does P0606 mean?

P0606 is a generic OBD2 powertrain code. It means “ECM/PCM Processor” — the same on every make and model, because the definition comes from the SAE J2012 standard rather than from the carmaker. The engine computer runs self-tests on its own memory and processor, and one failed: a processor fault (P0606), a memory checksum error (P0601) or a read-only memory error (P0605).

Can I drive with P0606?

With caution. If the car runs normally, get it checked soon; if it stalls or goes into limp mode, don’t rely on it.

What causes P0606?

Low or unstable supply voltage and poor grounds; Software that needs updating — many makers publish fixes for these codes; Water damage or corrosion at the module or its connectors; A failed control module.

How do I clear P0606?

Fix the cause first, then clear it with any OBD2 scanner or app. Once the fault is gone the car also clears it on its own: the check engine lamp goes off after the self-test passes on three drive cycles in a row, and the stored code ages out after about 40 warm-ups. Clearing without a repair only hides it for a while — and resets the readiness monitors an emissions inspection looks at.

Is P0606 the same on every car?

Yes. P0606 is a generic SAE J2012 code, so its definition is identical on every make and model. What differs is the cause behind it and the repair procedure, which depend on the engine — that’s why the assistant on this page asks for your car.

Guides

Definitions: the generic SAE J2012 codes from Brimly’s offline dictionary (data version 2026.09). Causes and advice are general guidance for all makes — the service information for your car has the last word.

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