P0627 code definition
The P0627 code is stored where there is a malfunction detected within the fuel pump A control circuit. This malfunction may have been detected by the PCM, or any of the supporting control modules, particularly the ECM.
What the P0627 code means
If the PCM has stored this code, it means that when the ignition switch is turned on, the ECM attempted to run the in-tank fuel pump or the fuel pump relay, but a malfunction occurred. There is not a particular circuit that is designated by this code; the “A” refers to an area of malfunction – in this case, the fuel pump control circuit in general.
What causes the P0627 code?
There are only a few possible causes for the P0627 code to be stored. Those include:
- A defective fuel pump
- A defective fuel pump relay
- Electrical components in the CAN Bus harness, like wiring or connectors, that are corroded, open, or short
- Loose control module ground strap
- Broken control module ground wire
- Defective CAN Bus
- Poor electrical connection in the fuel pump circuit
- Open or shorted fuel pump harness
What are the symptoms of the P0627 code?
The only symptoms that are commonly observed are the stored P0627 code, and the illumination of the Check Engine lamp. In many cases, the Check Engine lamp is not illuminated, and the stored code is shown as “pending” in the PCM.
How does a mechanic diagnose the P0627 code?
The first step to diagnosing a trouble code is to use an OBD-II scanner to verify the code. After the mechanic has used a scanner to detect the P0627 code, they will begin the diagnostic procedure by visually inspecting all of the wiring and other electrical components related to the CAN Bus and the fuel pump. Any shorted, open, or corroded elements will be repaired or replaced.
The PCM should then be cleared, and the system should be retested. If the code reappears, the mechanic may then move on to other repair options. A specialized scanner, such as an Autohex or a specialized CAN scanner, may be required to determine the specific area of the malfunction within the bulk of the electrical components that could be involved.
Common mistakes when diagnosing the P0627 code
When the P0627 code is stored, it is likely that several other codes will be stored due to the breakdown in communication between modules. These codes are often repaired by mistake, when the fuel pump or related issues were to blame. If the P0627 code is stored alongside others, it is important to check that this code is not the one to blame before repairing other issues.
How serious is the P0627 code?
If the P0627 code is being detected, the vehicle should be repaired as soon as possible. While no symptoms may be experienced, this issue can lead to serious malfunctions, decreased performance, or eventual breakdown.
What repairs can fix the P0627 code?
In order to address the cause of the P0627 code, a mechanic may do any of the following repairs:
- Replace a defective fuel pump
- Replace a defective fuel pump relay/
- Replace or repair any electrical components in the CAN Bus harness, like wiring or connectors, that are corroded, open, or short
- Adjust a loose control module ground strap
- Replace a broken control module ground wire
- Replace a defective CAN Bus
- Repair a poor electrical connection in the fuel pump circuit
- Replace or repair an open or shorted fuel pump harness
Additional comments for consideration regarding the P0627 code
When performing diagnostic tests or repairs related to this code, the mechanic should always clear the code and retest the system after every attempted repair. Without performing this step, the mechanic may not know what repair solved the issue, and might have wasted time and money on some repairs that weren’t necessary.
Need help with a P0627 code?
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