How can you tell if a PCM fuse is bad?

The failed PCM relay will turn off the dashboard lights and other key safety warning lights that are normally illuminated when you turn the key in the ignition. Furthermore, and more importantly, the vehicle will usually be unable to start and it might be impossible to turn the key.

What does the ECM battery fuse do?

The ECM 1 is one such computer; it has a fuse is installed to protect the computer from sudden power surges or other component damage — the fuse will blow before any damage can reach the ECM.

Is the ECM power supply lost with ignition turned on?

RE: ECM power supply lost with ignition turned on… So I replaced the ignition switch and found a few wires on top of the transmission that were rubbed through. Rerouted those and secured them properly to no avail. All can think of now is that there is a DPF sensor involved some way, somehow. A quick scan is showing 3 active codes.

What are the signs of a failing ECM?

Common signs of a failing PCM/ECM/ECU include the Check Engine Light coming on, engine performance issues, and the car not starting. 1. Check Engine Light Turns On 2. Engine Stalling or Misfiring 3. Engine Performance Issues 4. Car Not Starting

How does a bad ECM affect fuel economy?

Poor Fuel Economy. A faulty ECM disallows your engine from knowing how much fuel to burn in the combustion process. Typically, the vehicle consumes more fuel than it should in this situation. You’ll end up paying more for gas than you would with a functioning ECM. The ECM plays a vital role in engine performance.

How does the engine control module ( ECM ) work?

The ECM takes the information from the engine’s various sensors, and uses that information to calculate and tune engine spark and fuel for maximum power and efficiency. The ECM plays a crucial role in newer vehicles, where many (if not all) of the essential functions of the car are controlled by the ECM.

What does intermittent ECM / PCM power input signal mean?

ECM/PCM Power Input Signal Intermittent What does that mean? This is a generic powertrain code, which means it covers all makes supporting OBD-II protocol. However, specific troubleshooting steps will vary depending on the vehicle.

What causes a battery to go dead on an ECM?

Battery drain or dead battery A failed ECM power relay can also cause a battery drain or dead battery. If the relay shorts it can leave power on to the computer, even when the vehicle is turned off. This will place a parasitic drain on the battery, which will eventually cause it to go dead.

What to do when your ECM signal is bad?

Start the engine and use the voltmeter to check the voltage at the battery terminals. If the voltage is less than 13.5 or more than 15 volts the regulator is bad in the alternator. Shut the engine down and replace the alternator. If the voltage was 13.5 or better and less than 15 volts proceed to the next check. Check for parasitic drain.

What does p2509 power input signal intermittent mean?

However, specific troubleshooting steps will vary depending on the vehicle. The generic trouble code P2509 power input signal intermittent refers to an engine with an intermittent electrical signal to the Electronic Control Module (ECM) otherwise also known as a PCM or Powertrain Control Module.