2015-2020 Ram ProMaster 1500, 2500 & 3500 ECM: Your Guide to Part 5150926AB

Symptoms of a Failing Ram ProMaster ECM

A faulty ECM can cause a wide range of problems that may seem unrelated. Because the computer controls the entire powertrain, symptoms can range from a simple warning light to a van that won't run at all. Be aware of these common signs of failure:

• Complete No-Start Condition: The most common and severe symptom is a "crank, no-start" situation. The engine will turn over but will not fire up because the ECM is not commanding the fuel injectors or ignition coils to work.
• Engine Stalling: The engine may stall unexpectedly while driving or when coming to a stop. This can be extremely dangerous, as it results in a loss of power steering and can happen without warning.
• Check Engine Light with Internal Fault Codes: A major red flag is a check engine light with codes indicating an internal computer failure. The most common codes for this are P0601 (Internal Control Module Memory Checksum Error 🎬 See: How to diagnose and fix a P0601 code) and P0606 (ECM/PCM Processor Fault). These codes mean the ECM has failed its own internal self-test and can no longer be trusted.
• Poor Engine Performance: You may notice a sudden loss of power, hesitation during acceleration, rough idling, or a significant drop in fuel economy.
• Communication Issues: A failed ECM may not be able to communicate with a diagnostic scan tool, making it impossible to read codes or diagnose other problems.
• Problems Seemingly Caused by Other Parts: Sometimes, a failing ECM will set codes for various sensors (like crank or cam sensors) even if the sensors themselves are good. This happens when the computer's internal logic fails, leading to misinterpretation of sensor data.

Known Issues, Recalls, and Technical Service Bulletins (TSBs)

While there are no widespread recalls specifically for the ECM on 2015-2020 ProMaster vans with the 3.6L engine, related issues are documented.

• TSB for Software Updates: Earlier model years had Technical Service Bulletins (TSBs) issued to address certain powertrain control issues, including codes like P0606, by reprogramming (or "flashing") the ECM with updated software. This highlights that some issues can be software-related rather than a complete hardware failure.
• Cooling Fan Recall: A major recall was issued for 2018 and newer ProMaster vans for a cooling fan module that could overheat and cause a fire. While this is not the ECM itself, a major electrical event like a fire or short circuit in a related system can potentially damage the ECM.

Buying a Used Engine Control Module (ECM)

Purchasing a used OEM ECM is a cost-effective way to get your ProMaster back on the road, but careful verification is required to avoid compatibility problems. This is not a simple plug-and-play part.

1. Verify Your Part Number is 5150926AB

The most critical step is to match the part number on your original ECM. For this range of ProMaster vans, the correct part number is typically 05150926AB, 5150926AB, or P05150926AB. These prefixes (0, P) are often variations in Mopar's numbering system and do not change the part's function. The core number, 5150926AB, is what matters. Do not install an ECM with a different part number, even if it looks identical.

2. Confirm Engine and Transmission Compatibility

This specific ECM is for models equipped with the 3.6L V6 gasoline engine and an automatic transmission. It will not work on diesel models.

3. Check for the VSIM (Vehicle Systems Interface Module)

To check if your van has VSIM, look behind the cupholders in the center of the dashboard. If you see a module with extra wiring harnesses for upfitter equipment, you likely have VSIM and will need a different ECM.

4. Plan for Programming

A used ECM will not start your vehicle until it is programmed. Some sellers offer pre-programming services where they flash the used module with your vehicle's VIN before shipping it. This can make the installation much easier. If you buy a module that is not programmed, you must have it towed to a dealer or a shop with the proper tools.

5. Physical Inspection

When your used part arrives, inspect it carefully. Look for corrosion on the connector pins, cracks in the casing, or any signs of water damage. A clean, undamaged module from a reputable recycler is your best bet.

Programming and Installation

The physical replacement of the ECM is simple, but the electronic programming is complex and mandatory.

ECM Location

On the 2015-2020 Ram ProMaster, the ECM is located in the engine compartment, typically mounted to the firewall on the passenger side. It is a silver metal box with two or three large electrical connectors.

Installation and Programming Steps

1. Disconnect the Battery: Always disconnect the negative battery terminal before working on any electronic components.
2. Remove the Old ECM: Unplug the large electrical connectors. There are usually locking tabs that need to be released. Then, unbolt the module from its mounting bracket.
🎬 Watch: Step-by-step PCM swap and physical installation
3. Install the Replacement ECM: Bolt the new module in place and securely reconnect the electrical connectors. Reconnect the battery.
4. Mandatory Programming: At this point, the vehicle will not start. The red security light on the dash may flash, and the scanner may show a P0513 (Invalid SKIM Key) code. The vehicle must be taken to a Ram dealer or a properly equipped independent shop.
5. Programming Procedure: A technician will use a diagnostic tool like the wiTECH to perform the "PCM Replacement" procedure. This involves writing your van's Vehicle Identification Number (VIN) to the new module and synchronizing it with the Sentry Key Immobilizer Module (SKIM) so it recognizes your keys.

Who Can Program a Ram ECM?

• Ram Dealerships: This is the most reliable option. They have the factory tools (wiTECH) and software access required to perform the programming correctly.
• Specialized Independent Shops: Some high-end independent shops invest in the expensive tools and software subscriptions needed for Chrysler/Ram programming. You must call ahead to confirm they have the capability for a PCM replacement on a ProMaster.
• Pre-Programmed Modules: Buying a module that is pre-programmed to your VIN is often the easiest path for DIY installation, as it turns the job into a simple physical swap.

Frequently Asked Questions (FAQ)