|Trouble Code||Fault Location||Probable Cause|
|P069E||Fuel Pump Control Module Requested MIL Illumination||-|
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What Does Code P069E Mean?
OBD II fault code P069E is a generic code that is defined as “Fuel Pump Control Module Requested MIL Illumination”, and is set when the PCM receives a request from the Fuel Control Module to illuminate a warning light because a fault has occurred somewhere in the fuel system. Note that this code affects applications with electronically controlled returnless fuel systems, and that the types of faults that trigger this code are typically those that are likely to affect emissions.
Unlike older fuel systems that bleed off excess fuel pressure by returning some fuel to the tank, return-less systems use a dedicated, stand-alone fuel control module to vary the fuel pump’s speed as a means to control fuel pressure. While these systems have the practical advantage that evaporative emissions are reduced because there is less agitation and heating of the fuel, the added circuitry that comes with the system has increased the likelihood of failures and malfunctions occurring.
As a practical matter however, the PCM uses input data from various sensors to calculate the fuel pressure required to satisfy the current operating conditions. For instance, the current fuel pressure, throttle position, and engine speed (among several other parameters) at a steady cruising speed serve to control/limit the fuel pump’s speed, and thus fuel pressure, to a speed that satisfies the current fuel requirements. So, should the throttle position change, such as might be expected to happen during acceleration, the PCM will re-evaluate all input data, and instruct the Fuel Control Module to increase the fuel pump’s speed to a point where the new fuel requirements can be satisfied.
Note however that since returnless fuel systems do not have the ability to bleed off excess pressure, the system relies on very accurate data from the fuel pressure sensor in order to avoid both over-, and under fuelling conditions. The fuel pump has to meet fuel requirements exactly, so should any sort of fault occur that makes it difficult or impossible for the Fuel Control Module to control the fuel pump’s sped effectively, the Fuel Control Module will request the PCM to illuminate a warning light, and to set code P069E in the PCM.
Note that in some cases, the actual faults that triggered the warning light illumination request may be stored in the Fuel Control Module, while in other cases the actual faults might be stored in the PCM. In practice, this means that if the faults are stored in the Fuel Control Module, professional-grade diagnostic equipment is required to extract and clear the codes after repairs are complete.
The image below shows a Fuel Control Module that had failed because of corrosion of the metal casing. Note that the appearance and location of Fuel Control Modules vary greatly between applications, and can be located almost anywhere in/on the vehicle. Always refer to the manual for the application to correctly identify and locate components, and especially in the case of Fuel Control Modules, since they are sometimes easy to confuse with a PCM.
What are the common causes of code P069E?
Common causes of code P069E could include the following-
- Damaged, burnt, shorted, disconnected, or corroded wiring and or connectors
- Defective fuel pump relay
- Defective Fuel Control Module
- Defective fuel pressure sensor
- Failed or failing PCM. Note that while this is not altogether impossible, it is more likely for the Fuel Control Module to fail
What are the symptoms of code P069E?
Common symptoms of code P069E could include the following-
- Stored trouble code and illuminated warning light
- In some cases, there may be no discernible symptoms other than a stored code and a warning light
- Depending on the nature of the problem, a no start, or hard starting condition may be present
- Idle speed may fluctuate, or the engine may not idle at all
- In some cases, there may be a degree of power loss across the engine’s operating range
- Other codes may be present along with P069E, and especially codes that relate to emissions, although non-emission related codes may be present as well
- Fuel consumption may increase in some cases
How do you troubleshoot code P069E?
NOTE #1: Apart from a repair manual for the application being worked on, a wiring diagram and a good quality digital multimeter, a dedicated fuel pressure gauge is required to diagnose this code accurately.
NOTE #2: Be sure to check the system/battery voltage before starting a diagnosis of this code, since on some applications, the fuel pump may be deactivated if the battery voltage falls below a critical level.
NOTE #3: On applications that use active grille shutter systems, failures or malfunctions in this system can sometimes either trigger code P069E or contribute to the setting of code P069E. If codes relating to the active grille shutter system are present, investigate and resolve these codes first, before attempting a diagnosis/repair of P069E. Failure to do this could result in a misdiagnosis, wasted time, the unnecessary replacement of parts, and a repeated recurrence of code P069E.
NOTE #4: In order to ensure an effective repair (and to save time) clear all codes and operate the vehicle for at least one complete drive cycle after each diagnostic/repair step before scanning the system again to see if the code returns. Keep in mind that it is important to complete a drive cycle as per the instructions in the manual to ensure that the fuel pump has the opportunity to work through its entire operating range.
Record all codes present, as well as all available freeze frame data. This information can be of use should an intermittent fault be diagnosed later on.
Refer to the manual to locate and identify all components correctly. Also determine the routing, function, and color-coding of all associated wiring, and especially the wiring that is associated with the fuel pressure sensor.
NOTE: Be sure to locate and check all fuses, fusible links, and relays that are associated with the fuel system. If any fuses or fusible links are blown, do NOT replace them until the cause of the short circuit or overload had been identified and corrected.
If the engine starts and runs, locate the dedicated fuel pressure testing point; however, do not start the engine before attaching the fuel pressure gauge to this point. To prevent the possibility of an engine fire, only start the engine once it is certain sure that the gauge is attached securely.
NOTE: If a no-start condition is present, go to Step 6.
Perform the fuel pressure test as per the instructions in the manual to ensure the most accurate test results. Note that the manual will specify the minimum and maximum allowable deviations from the system’s design pressure. If the obtained reading falls outside of these limits, do not condemn the fuel pump out of hand just yet- it is possible that the fuel pressure sensor is defective, and is supplying the Fuel Control Module/PCM with inaccurate data.
Locate the fuel pressure sensor, and perform a thorough visual inspection of all associated wiring. Look for damaged, burnt, shorted, disconnected, or corroded wiring and connectors, and make repairs or replace wiring as required.
If no visible damage to wiring is found, perform resistance, reference voltage, ground, and continuity checks on all its associated wiring. Be sure however to disconnect the sensor from the PCM and /or Fuel Control Module to avoid damage to the controller(s).
Compare all obtained readings with the values stated in the manual, and repair or replace wiring as required to ensure that all electrical values fall within the ranges specified by the manufacturer. If all electrical values check out, test the resistance/continuity of the fuel pressure sensor itself; replace the fuel pressure sensor if it does not conform to the manufacturers’ specifications.
If the fault persists, but the fuel pressure checks out as per the values stated in the manual, locate all wiring that is associated with the Fuel Control Module. Perform a thorough visual inspection of this wiring between the Fuel Control Module and the PCM- look for damaged, burnt, shorted, disconnected, or corroded wiring and connectors, and make repairs or replace wiring as required.
If no visible damage to wiring is found, perform resistance, reference voltage, ground, and continuity checks on all its associated wiring. Be sure however to disconnect all relevant wiring from the Fuel Control Module and PCM to avoid damage to the controller(s). Make repairs or replace wiring as required to ensure that all electrical values fall within the ranges specified by the manufacturer.
If all electrical values check out, replace the Fuel Pump Control Module, especially if there are any signs of corrosion on the casing if the module is made of metal.
If a no-start condition is present, locate all relevant wiring, and perform a thorough visual inspection on all wiring, and especially the wiring between the Fuel Control Module and the fuel pump. Look for damaged, burnt, shorted, disconnected, or corroded wiring and connectors, and make repairs or replace wiring as required.
If no visible damage is found, perform resistance, reference voltage, ground, and continuity checks on ALL associated wiring, and be sure to check the condition of fuses and fusible links in the circuit, as well as the operation of all relays. Be sure however to disconnect all relevant wiring from the Fuel Control Module and PCM to avoid damage to the controller(s). Make repairs or replace wiring/connectors/fuses/relays as required to ensure that all electrical values fall within the ranges specified by the manufacturer.
If it is certain that all wiring is free of faults and defects but the fuel pump will not start, refer to the manual on the correct procedure to follow to test the pump (and the pressure it delivers) with a current drawn directly from the battery. Be aware though that removing a fuel pump on some applications may require removal of the fuel tank, so consult the manual on the correct procedure to gain access to the fuel pump.
If the fuel pump starts and delivers its design pressure when a direct current is applied, suspect either a defective Fuel Control Module, or a defective PCM. Bear in mind however that the Fuel Control Module is far more likely to fail than the PCM, so do not condemn the PCM out of hand until the Fuel Control Module had been replaced.
If however, the fuel pump starts when a direct current is applied but it does not deliver its design pressure, replace the pump with an OEM part to prevent a recurrence of the problem.
Note that on some applications, completing multiple drive cycles may be required before this code can be cleared. Thus, if the fault does not return after having completed the required number of drive cycles, the repair can be considered as successful.
If the fault does return, it is likely that there is intermittent failure, which can be extremely challenging to find and repair. In extreme cases, it may be necessary to allow the fault to worsen considerably before an accurate diagnosis and definitive repair can be made. Note however that an intermittent electrical fault in the fuel system can cause the fuel system to fail unexpectedly, with possible dire consequences should this happen in heavy traffic.
From a safety perspective, it is highly recommended that in cases where an intermittent fault is suspected, the vehicle be referred to the dealer or other competent repair facility for professional diagnosis and repair.
Codes Related to P069E
There are no known codes that are directly related to P069E – “Fuel Pump Control Module Requested MIL Illumination”.
BAT Team Discussions for P069e
- 2008 GMC Van no Start
Vehicle: 2008 GMC Cargo Van 4*4 The eight digit of the VIN is 4 and the tenth digit is 8 20000kms The above vehicle has a no start condition. I cranked the engine and sprayed some gas into the intake and it runs. We scanned the vehicle and it came up with code P069E. (Fuel pump module sh...