What the P0656 code means?
The P0656 means that something in the fuel level output circuit's electrical connections or wiring, which run from the PCM to another controller interface module, is malfunctioning. The PCM gathers data from the engine in order to feed the most important information to the other electrical modules. Flawed information coming from one of the output circuits in the PCM can greatly impact the performance of the system.
What causes the P0656 code?
The most common cause of this code being stored comes from defects in system circuitry. Loose, broken, or corroded wiring and electrical connectors are common and should be investigated first. Other possible causes include a defective PCM, faulty low fuel level indicator bulb, or fuel level sensor. If there are other codes related to fuel level, that were stored prior to this code being stored, diagnose and repair those before attempting to diagnose this code. Freeze frame data can be useful when diagnosing this code.
What are the symptoms of the P0656 code?
1. inoperative fuel level gauge
2. Low fuel lamp is inoperative
3. Low fuel lamp remains illuminated
4. Engine drivability issues
5. Fuel temperature codes
6. Evaporative emission system codes
Common mistakes when diagnosing the P0656 code
Technicians report that the engine coolant temperature sensor is often replaced in error when the PCM driver is at fault.
What repairs can fix the P0656 code?
1. A technician should verify the code with a scanner, and begin repairing the issue by resetting the codes and doing a road test to determine if the P0656 code returns. If so, they must then move on into a more in-depth diagnosis.
2. The next step is to do a visual inspection on the PCM and the wiring harnesses, ground wires, and connectors. Anything that is frayed, corroded, disconnected or damaged must be replaced and the diagnostics re-run to determine if the code will reappear.
3. If the code returns, it is necessary to examine the system circuitry. This may require the use of an or Tech II scanner that looks into the CAN bus to detect the problems. Because the most common cause for this code is loose or disconnected wiring, the diagnostic CAN scanners are typically the most effective in finding the issue and making the repair.