P0601: Internal control module memory checksum error

What P0601 means

At start-up the ECU checks that its program and data are intact using a kind of control sum. This code means that sum does not match, so the memory or software may be damaged. Sometimes reprogramming sorts it out, other times the unit has to be replaced.

Most common causes

• Low battery or power loss during a software update
• Incomplete or corrupted ECU programming
• Badly done engine software modification
• Moisture, impact or heat damage to the ECU
• Internal memory fault in the ECU

Symptoms

• Engine warning light on
• Engine may not start, or start and then stall
• Rough running or limp mode

Can you drive with P0601?

With care If the car starts and runs well you can drive carefully, but it could fail without warning. Take it soon to a garage that can reprogram ECUs.

How to check it

First make sure the battery is well charged and the terminals tight, then clear the code and see if it returns. If it does, ask the garage or dealer whether there is a software update for your ECU.

How to read and clear P0601 with Final OBD

Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see P0601 with this same explanation and whether it’s confirmed, pending or permanent.

With Free you read this code with its short description for nothing, and clear it if the engine stores it over standard OBD. With Pro you get the full explanation, how the car was running when it was logged (revs, temperature, load) and clearing in every control unit.

Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before the ITV. It’s all in how to read and clear fault codes and in the ITV and OBD.

Similar codes

• P0600 Serial communication link fault
• P0602 Control module programming error
• P0603 Internal control module keep alive memory (KAM) error
• P0604 Internal control module random access memory (RAM) error
• P0605 Internal control module read only memory (ROM) error
• P0606 ECM/PCM processor fault
• P0607 Control module performance
• P0615 Starter relay: circuit fault
• P0616 Starter relay: circuit low

P0601 is a generic code, so it means the same on any make, for example on Alfa Romeo, Dacia, Kia, Opel / Vauxhall, Toyota, Škoda. See what Final OBD does on your car in makes and models.