Powertrain Control Module and How to Detect Any Problems: A PCM is a modern computer that receives all inputs from the system of the vehicle and instantly uses that information to deliver appropriate engine power for appropriate working conditions.
How does the PCM work?
The PCM is powered by the battery power and programmed to send electricity at a regulated voltage to engine sensors as well as other control units on the network. Every other system in the vehicle solely depends on the information from the PCM to function properly. The data is simultaneously passed back into the PCM to monitor the conditions as well as to be monitored at all times.
What symptoms can you detect in a poor PCM?
When the PCM starts to fail, you can easily tell as it starts to make erroneous calculations, fails to connect and fails to interpret the date correctly or generally fails to operate at all. This leads to constant malfunctions in most systems in the vehicle because every system is highly dependent on the PCM data.
This triggers the check engine light to come on and a computerized scanning tool or handheld scanner to check the condition of the compare car. The symptoms of the PCM depends on the portion of the PCM damaged but in most cases, when a PCM fails, the entire vehicle fails and does not start or run.
Can I drive with a PCM problem?
No! In most cases, driving a car that has a failed ECM is impossible. This is because the systems required to run the vehicle are not being instructed. The PCM is a vital computer and if it happens to send any erroneous messages, the vehicle will not even start. In such a case, the vehicle should be towed to a repair facility.
How often should a PCM need to be replaced?
The powertrain control module is known to fail frequently in small groups of vehicles. For example, a clean Ford PCM can serve you for over 130,000 miles before it fails or develops any problems. This is normal as many vehicles will crush with the original PCM in place as early as 75,000 miles up to 125,000 miles, which is common to many vehicles.
How are the PCM issues diagnosed?
Anytime you suspect a failure of the PCM, contact a professional technician as early as possible so that it can be checked. The PCM should be tested by comparing actual readings to specified readings and following a diagnostic process that tests the necessary parameters.
There are many possible failure symptoms and it is not possible to speculate which pin to check. The reference material is able to guide the technician to know what to check.
How is a powertrain control module replaced?
Replacing a faulty PCM is easy! The technician needs to check the exact location in which the PCM is placed by the manufacturer. Some are placed in the engine bay while others are inside the vehicle or even the trunk.
Once the PCM is located, obstructions to testing are removed and the testing starts. If the diagnostic testing fails, then the PCM is unplugged, replaced and reconnected to the vehicle before it is fully assembled and tested.