Error Code P1245 is defined as Alternator Load Input Failed Low.
This error code is a generic trouble code, meaning it applies to all cars equipped with OBD-II system or cars made since 1996 up to present. Specifications, troubleshooting, and repairs, of course, vary from one make and model to another.
The PCM (powertrain control module, also known as ECM or engine control module in other 2003 Mercury Grand Marquis makes) monitors generator load from the generator or regulator in the form of frequency. The Error Code P1245 means the input is below the specified load for normal operation. This could happen when there are no generator output exits.
This code activates the Check Engine light, which is also usually its only symptom.
Many factors lead to this error code. Some of the most common possible causes include:
To diagnose for this error code, technicians usually start by checking the alternator/generator for signs of damage and malfunction.
Then, they proceed on checking the alternator belt if it’s still in good running condition.
Next, they check for open or shorted harness of alternator/generator.
Next, they check for any signs of burnt, damaged, or scuffed electrical wirings in the alternator/generator circuit.
Repairs for this error code are easy, but of course, successful repair can only be made possible through a thorough diagnosis of the problem. For the repairs, however, some of the most common fixes are:
PCM damage is usually the last resort if all things fail in diagnosis. It’s quite a rare condition, but can be possible.