Will a bad PCM drain battery?
Lastly, a failed PCM relay can cause the battery to drain over time due to the switch constantly being turned on, or a dead battery. If they relay short circuits, it can drain the computer battery, even when the vehicle is turned off.
Do you need a PCM to test a battery?
You may not get PCM communication if the voltage to it is off as well. Need to be going after battery WAY before PCM, it being low can blow your mind with various oddball errors. You need to verify both battery and alt charging, they could be fooling you…………….need at least 12.3 volt or more at battery.
Why does my PCM fail every time I replace it?
PCMs typically fail for one of two reasons: voltage overloads (often due to a short in a solenoid or actuator circuit) or environmental factors (corrosion, thermal stress or vibration). If the shorted solenoid or actuator isn’t found and repaired, the voltage overload it creates may damage the replacement PCM, too.
Can a bad PCM cause a car to not start?
This can be caused by several different PCM errors, but may also be an indication of something wrong in your ECM. Regardless, this is a serious problem, since your car could potentially fail to start when you’re stranded on a country road, in an empty parking lot, or any number of undesirable locations. 3. Sudden Loss of Gas Mileage
Why does my PCM not work at low volts?
Could be partial power from your gauge sweep issue too, pumps get wonky at low volts. You may not get PCM communication if the voltage to it is off as well. Need to be going after battery WAY before PCM, it being low can blow your mind with various oddball errors.
Can a bad PCM cause a car to run poorly?
In other cases, the vehicle may run poorly. Continuing to run a vehicle with a bad PCM could cause further damage. Because the PCM controls the emissions of your car, a failed emissions test or the presence of oddly-colored or foul smelling exhaust may be a sign that your PCM is going bad.
Can a bad alternator cause a bad PCM?
If these are all good, then you need to check the wiring between the PCM and the alternator, or the PCM itself may have a problem. Another possibility is a bad Battery Temperature Sensor.
What happens if your PCM is not working?
The PCM is also designed to control both ignition timing and spark. Problems with the PCM often result in the vehicle not running at all. In other cases, the vehicle may run poorly.
What happens if my PCM fails the emissions test?
This may cause you to fail your state’s emissions test. If your car does fail, check your PCM and ECM first. Believe it or not, a failed PCM or PCM may actually be good news: replacing either of these systems is significantly cheaper than getting a new catalytic converter.