The Engine Control Module (also called the Powertrain Control Module or PCM) is often called the “brains” of the engine management system. It controls the fuel mixture, ignition timing, variable cam timing and emissions control. It oversees the operation of the fuel pump, engine cooling fan and charging system. It also interacts with the transmission controller (if separate), ABS/traction/stability control system, body control module (BCM), climate control module and anti-theft system. In short, the ECM performs a wide variety of functions that are necessary to operate a vehicle.

Note: The Engine Control Module (ECM) and Powertrain Control Module (PCM) are sometimes confused for one another. The ECM monitors the sensors found on the engine while the PCM handles the drive train sensors.

What are the Symptoms of a Bad ECM?

  1. Engine Performance Issues, Running Poorly

When the readings from the engine’s sensors are not interpreted correctly, the result may be a rough running vehicle due to fuel cutoffs, accessory power failures or ignition issues. The fuel mixture must be correct. If it is not getting enough fuel, it will cough, choke, sputter and may even stall. If it is getting too much fuel, your fuel economy will decrease and your exhaust emissions will increase.

  1. Engine Stalling, Misfiring, Will Not Run

In some cases, an ECM problem will cause the vehicle not to run at all. The ECM’s functions include positioning the crankshaft and controlling the ignition spark and timing. If there are problems with how the ECM performs these functions, the vehicle may not run and the ECM may have incurred damage.

  1. Check Engine Light (CEL) or Other Dashboard Error Lights

If your ECM is malfunctioning, you can expect to see almost every error light imaginable appear and disappear at some point. The ECM controls and interprets sensor readings, so if it is not doing this properly, you can expect to see your “Check Engine Light”, “Service Engine Soon” light, “ABS” light, and a variety of others illuminate or flash on and off.

  1. Emissions

The ECM controls your vehicle’s fuel and emissions system. If your ECM is not functioning properly, your car may fail its emissions test, emit too much smoke, emit colored exhaust (white, blue or black, depending on the issue) and may smell like fuel.

  1. DTC: Internal ECM Malfunction

P06XX series codes in most vehicle lines indicate an internal ECM malfunction. Many repair facilities will replace and program the ECM based on these codes. However, in many cases, the cause is associated with faulty O2 sensors, ignition coil issues, or harness issues; all of which are repairable.

Call the professionals at ModuleExperts for help if you experience any of these symptoms. Our knowledgeable and experienced Parts Associates will be happy to provide information on the best and quickest solution to get you back on the road faster.

ModuleExperts brings more than 100 years of combined experience in module diagnostics, repairs and remanufactured replacements for all types of control modules. Our A+ BBB rating proves our commitment to first-class customer service and satisfaction. Contact us today to learn more about how we can help service your control module needs.