OBDII DTC Trouble Code P1605 can be typically found in Ford vehicles, and today we’ll be showing you how to resolve this issue in a 2007 Ford Fusion SE. This OBDII trouble code refers to the Keep Alive Power Circuit found as part of the Powertrain Module.
The OBDII DTC code of P0603 can also be generated and can also accompany the P1605.
Symptoms of a Ford P1605 DTC will include MIL (Malfunction indicator lamp) illumination, although there may be other symptoms, including but not limited to, engine stall, various warning lights on dash, module communication codes, no start conditions.
If you have a Ford OBDII trouble code and have this error the often asked question is; What does this mean? Keep Alive memory is part of your vehicle’s PCM and stores data on drive cycles based on sensor outputs and vehicle speed.
This data is then referenced to maximize fuel economy and available power depending on your driving style as well as shift points in relation to how you drive your car.
Ford deems this information vital to the operation of your vehicle, and will not cause “limp mode” but rather the PCM will operate the vehicle on basic programmed values. This can lead to inefficient gas mileage and problematic idle issues if left unattended.
If your vehicle has recently had it’s battery disconnected or an ignition or PCM related repair, or had the KAPWR interrupted to the ECU. The DTC P0603 or P1605 can turn on for the vehicle’s first run since the repair.
If your vehicle has not had any such repair, or the battery disconnected we can begin the steps to diagnose DTC P1605 or P0603.
Step 1: Inspect all battery terminals and wire ends for corrosion or damage. Make sure your keys are in the “OFF” position as you inspect these components.
Step 2: Check battery for voltage or have your battery tested
Step 3 : Check proximity of Electronic Engine Control wiring and make sure this engine harness is not extremely close to any ignition related parts. If it is reroute them away from your ignition components.
Step 4: Find your vehicle’s ECU pinout and refer to the KAPWR circuit on the PCM harness. Using a voltmeter inspect the wire from the PCM to the dash panel. The voltage for this wire should read higher than 10.5 volts, if not you must isolate and repair the either the wire or ECU.
Take this time now to inspect the PCM cavity for any water leakage or rundown, this issue is common with the Ford
Step 5: Reset your PCM by disconnecting the battery and turn the vehicle on with your alternator disconnected. Does the code return with the alternator disconnected?
If your terminals and battery seem solid and without corrosion, and the ecu and harness seem to check out you may look into testing the continuity from the ECU / PCM to your battery.
And lastly if your vehicle is equipped with an aftermarket chip or out of the box programmer such as the Hypertech, this may complicate the issue.
If all these have checked out and your issue still remains, make sure your Ford ECU has been updated or flashed it’s EEPROM.
For more OBDII coverage and articles, check out our DTC Doctor.