The Powertrain Control Module or PCM on 7.3 Powerstroke engines controls the automated engine and transmission. PCM also enhances the engine performance by adjusting the Powerstroke engine in bad conditions.
But when the PCM fails, it gradually causes problems such as air to fuel ratio disbalance, transmission malfunctioning, and engine performance failure.
Therefore, let’s find out the reasons behind PCM failure, how to detect bad PCM on your 7.3 Powerstroke, inspect and replace it.
How Do I Know My 7.3 Powerstroke PCM Is Bad?
Often people replace PCM without even confronting the problem they were experiencing that was caused due to PCM failure or something else. As a result, even after replacing the PCM, the problem remains the same as before.
That’s why you need to know the exact signs to understand when something is wrong with your 7.3 Powerstroke PCM.
The most obvious sign that you may notice is when engine lights or other warning lights such as ABS and traction control abruptly turn on for no reason.
Besides that, encountering significant drop in engine’s fuel economy, gas mileage without any other valid reason may happen due to the Transmission Control Module malfunctioning, which also primarily indicates PCM failure.
Another very prominent warning that your PCM is gradually failing when you see abrupt or unnecessary shifting, which eventually cause engine misfiring, like backfires or frequent stuttering.
Even rough idling conditions, stuttering during engine starting or stalling, poor performance on acceleration can also cause when your PCM malfunctions.
What To Do After Detecting 7.3 Powerstroke PCM Failure Symptoms?
Here you need to stop for a second. Though those above-mentioned signs are pretty obvious indications of PCM failure, you still need to run a proper test to confirm and inspect the exact level of damage.
So, let’s learn together how to test your 7.3 Powerstroke PCM-
- First, check your battery voltage power using a digital voltage OHM meter. Your meter reading should be at least 12.6 Voltages when the engine is turned off and when the engine is on, it should read 13.7 volts. If your reading shows less than mentioned, you should fully charge your battery and retest it.
- After that, test all the wirings, grounds and network functionality with a rotunda integrated diagnostic system or IDs network test pings. Now look for response modules that do not respond are labeled. When a module reports a failure on the network test, it can be due to an aftermarket device’s incorrect installation. So, you need to do a thorough inspection of your aftermarket modifications.
- Next, inspect whether there is No Power or Ground Missing to the modules. Also, check whether one or both communication circuits open or shorted internal module hardware failure. This can affect more than one module’s ability to report.
- Then, check OBD2 connector terminals for pushed-out pins from the connectors.
Remember, one module which is damaged or bad can also cause other modules to report ‘No Communication’ trouble codes. Ultimately, it will cause you to incorrectly diagnose a viable module.
- Now, check all the diagnostic trouble codes or DTC modules that do respond when tested are asked to report any DTCs. Here, codebook is a necessity since you will need to learn what the codes mean to take the correct action.
How hard it is replace 7.3 Powerstroke PCM?
Replacing or installing a new PCM may sound like a complex process. But if you are familiar with the technical tools and tasks, it is not that difficult to do yourself. All you need is a Screwdriver and Sockets to replace your PCM.
Even several YouTube videos will help you to do both PCM testing and replacement task. In this way, you can save money too because replacing PCM from a professional or service center is quite costly.
Where is the PCM located on My 7.3 Powerstroke?
To locate your PCM, go to the driver’s side firewall and go beneath the brake master cylinder next to the fender. Now open the hood, you will notice the rectangle-shaped (approx. 1″ x 6″ with a 10mm bolt in the center) computer harness connector. It is the PCM connector, you are looking for.
How To Upgrade Or Replace Your 7.3 Powerstroke PCM?
Follow the following instructions to replace your PCM on 7.3 Powerstroke-
First, you need to follow the direction, which I mentioned earlier to locate your PCM along with that, you also have to locate the Strategy Codes for your module and service bulletins issued exclusively for your vehicle. After locating the PCM, now record your module and Strategy Code numbers.
Based on your previous findings, purchase a new module but before installing it, compare the new one with the existing one. Make sure the harness connectors and mounting locations match.
Tip: Most PCM connectors are generally protected by silicon, so make sure to clean the connector before installing the module for proper operation. Also, avoid re-using the PCM bolts since certain solvents can damage the PCM.
Now, you need to detach the battery cable, so disconnect the cable from your battery’s negative side.
Finally, time to switch the modules, so unbolt and detach your existing module. Before inserting the new one compares it with your previous module one more time since most shops or dealers will not return once you install it.
Reminder: It is strongly recommended to read the references given in your user’s manual and thoroughly follow the PCM module manufacturer’s recommendations.
When Should You Replace The 7.3 Powerstroke PCM?
As I have already explained the testing process, make sure you go through the detailed testing process first.
After confirming that other parts and components are functioning correctly through the computer diagnostic, check whether there is any glitch in the software. If so, simply install an updated version of the software.
Once you confirm, there are no other hardware or software issues rather than the PCM, only then you should replace it.
How Often Should I Check Or Replace My 7.3 Powerstroke PCM?
Experts or Ford authority have not suggested any scheduled time frame to check and inspect PCM on your 7.3 Powerstroke engine.
According to them, you should simply check the condition of your PCM whenever you are doing the routine servicing or inspection of your engine. You should run the computer diagnostic to check whether everything is in good condition or not.
Why Does PCM On 7.3 Powerstroke Fails?
The main reason behind the PCM failure is heat and vibration, which causes communication and coordination malfunctioning between different internal mechanisms.
The typical reason for a 7.3 Powerstroke or any other PCM failure is either voltage overloads or environmental conditions.
Here voltage overloads occur when you do not detect a short in a solenoid or actuator circuit on time and fix it.
Remember, if you do not repair the shorted solenoid or actuator before replacing the damaged PCM, the voltage overload will damage the new one afterward.
On the other hand, environmental factors mean corrosion, thermal stress, or vibration that mostly occurs due to water’s existence, so make sure water does not enter especially, inside your PCM.
In worst cases, it will cause a short circuit or irreversible corrosion and ruin all internal electrical connections.
The PCM on 7.3 Powerstroke engines controls and maintains the engine and transmission to lessen the stress of constantly monitoring all the parts. But PCM failure also causes performance and starting issues on 7.3 Powerstroke. Therefore, modifying or rebuilding the PCM on time will be the perfect solution to avoid those troubles. So, follow the instruction above to inspect and replace it.