P0606: Control Module Processor

A generic powertrain (engine and transmission) trouble code, same meaning on every brand.

Fix now, drive carefully

Cautiously and briefly - a computer distrusting itself can trigger limp mode or stalling unpredictably.

$100 - $2,000

typical repair range

NHTSA complaints mention this code

79,000

median mileage when reported, mi

Symptoms

Limp mode, stalling, or no-start
Code returns immediately after clearing

Likely causes, most common first

Engine computer internal fault (after externals ruled out)
Supply voltage or ground problems mimicking internal failure
Rare: software corruption fixable by reflash

Read P0606 yourself before paying for diagnosis

A basic Bluetooth OBD-II scanner ($20-40) plugs into the port under the dashboard and shows this code with live sensor data on your phone - useful both for confirming the fix and for talking to a shop from an informed position.

What is going on and how it gets diagnosed

P0606 is the engine computer failing its own self-test. Before the expensive conclusion, verify what feeds it: low supply voltage and bad grounds are notorious imitators of internal processor faults - the P0562 checklist applies here too.

A persistent P0606 with clean power and grounds usually does mean the module. Replacement requires programming to the vehicle, which is why the total lands near four figures even when the used part is cheap.

Repair options and cost

Power/ground circuit verification$100 - $250

PCM reflash$100 - $300

PCM replacement + programming$800 - $2,000

Typical US independent-shop ranges, parts and labor. Dealers run higher; regional labor rates vary.

Owner reports mentioning P0606

“The contact owns a 2017 Dodge Grand Caravan. The contact stated that while driving at an undisclosed speed, the vehicle experienced a loss of automotive power. The contact stated that several unknown warning lights were illuminated. The contact pulled over to the shoulder of the road and shift the vehicle into park(P); however, the vehicle was stuck in reverse(R), and failed to shift to neutral(N). The vehicle was towed to a local independent mechanic, where it was diagnosed and DTC: P1602 (PCM not Programmed) and P0606 (Error with PCM) were retrieved. The local dealer was not contacted. The manufacturer was not made aware of the failure. The failure mileage was approximately 150,000.”2017 Dodge Grand Caravan · Jun 2025 · 150,000 mi

“The contact owns a 2014 Ford Focus. The contact stated that the vehicle was repaired under Manufacturer Recall Number: 14M02. However, after the repair was completed, the vehicle started stalling while driving at various speeds, and the transmission failed to shift above second gear. The failure was intermittent but was a recurring failure. The vehicle was taken to the same dealer several times; however, the dealer was unable to repair the vehicle. The vehicle was taken to another dealer, who scanned the vehicle and retrieved DTC: P0606 and P0702. The vehicle was not repaired. The manufacturer was informed of the failure. The failure mileage was approximately 74,000.”2014 Ford Focus · Apr 2024 · 74,000 mi

“The contact owns a 2016 Ford Fiesta. The contact stated that the transmission control module failed after the battery was replaced. The dealer was made aware of the failure but informed the contact that there was no recall associated with the VIN. The vehicle was taken to an independent mechanic, who diagnosed that the TCM needed to be replaced due to error code P0606. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 100,000.”2016 Ford Fiesta · Dec 2022 · 100,000 mi

Show 7 more owner reports

“Check engine light is on - diagnosed as transmission control module is bad and needs to be replaced; however, the code (p0908) is not part of the extended warranty. The vehicle is showing all symptoms/behavior which if the code was p0606, replacement would be covered. If the tcm is bad, it's bad and ford should offer consideration - currently, the vehicle is not safe to drive!”2012 Ford Focus · Jul 2020 · 115,000 mi

“This vehicle only has 80000 mi and has a engine code of p0606. The computer malfunction and stopped at the light and almost caused an accident. Something needs to be remedied about this”2012 Ford Fiesta · Jul 2020 · 80,000 mi

“My pontiac has had a leak for 6 yrs basically since I had it and before that. I didn't think nothing of this but after a while of the sunroof leak it causes corrosion on the electrical terminals in the wire harness inside the dash on driver door side. This corrosion cause your car to throw pcm/tac codes : p0601,p0606,o0107. Causes car to complete stall out and go into reduced engine power mode. This can be extremely unsafe. I am not the only one there is a few hundred people who posted on sites trying to fix the same issue. Please look into this a lot of people don't know about this NHTSA to report recalls.”2005 Pontiac G6 · Mar 2020 · 185,000 mi

“Purchased new vehicle with less than 4,000 miles was running fine when parked. When it was cranked to go home listed esc failure, service steering column lock, trailering system failure, lane departure disabled, speed limited to 60 mph. I was able to get home, but the brakes were so hard that it was extremely difficult to stop. Local dealer it was purchased through "fixed it" less than 1,500 miles later I'm having the same issue! Obd has the codes c0021, c0021, p25a2, p25a2, p0606. I do not feel safe driving this truck! If that issue were to happen approaching an intersection I would have no way of stopping in time. Ridiculous.”2019 Chevrolet Silverado 1500 · Jan 2020 · 1,500 mi

“After remote start mychev app vehicle stationary four dash messages service esc service trailer brake brake system failure - 62 mph top speed steering assist reduced drive with care  lights on dash that were illuminated ABS check engine brake traction control tried to drive. Brakes and steering limited could not drive unsafe turned off ignition restarted threw five codes including p0606 c0021 p25a2 called onstar, they said all systems showing failed take to dealer called gm- they said to have it towed remote start again- same messages dealer appt tomorrow.”2019 Chevrolet Silverado 1500 · Jan 2020 · 13,000 mi

“Tl* the contact owns a 2019 chevrolet silverado 1500. While driving 60 mph, the check engine, stability control, traction control, and ABS warning indicators illuminated. Also, the "limited to 62 mph" message was displayed and the vehicle did not respond when the brakes were applied. The contact had to downshift for the vehicle to stop. The contact called onstar and was informed that codes: 925a2, p0606, and c0021 regarding the ecm, charging system, air bags, and transmission were detected. The vehicle was taken to gilbert chevrolet (3550 us-441, okeechobee, fl 34974, (863) 261-8947), but was not diagnosed or repaired. The failure mileage was 423.”2019 Chevrolet Silverado 1500 · Oct 2019 · 423 mi

“Engine revving to 3000 rpm and not idle down. Had to ride brakes put trans in neutral or park to stop. Breaks would not stop truck only slow it. Shop found cod p0606 ecm/pcm communication failure. Why did this not put the truck in limp mode or prevent it from starting. Replaced ecm/pcm control module truck runs fine. Very expensive 3400 dollars.”2004 Dodge Ram 3500 · Feb 2016 · 45,000 mi

Cars that report P0606 most often

Based on mentions of this code in NHTSA owner complaints.

Frequently asked questions

Can I drive with P0606?

Cautiously and briefly - a computer distrusting itself can trigger limp mode or stalling unpredictably.

How much does it cost to fix P0606?

Typical US repair costs range from $100 for the simplest fix (power/ground circuit verification) to $2,000 in the worst case. The right number depends on which cause your car has - see the causes list.

Definition per SAE J2012 standard nomenclature. Symptoms, causes and costs are editorial guidance - always confirm with a diagnosis of your specific vehicle.