P1001 – Key On/Engine Running Not Able to Complete (Ford, Lincoln, Mercury)

By Reinier (Contact Me)
Last Updated 2022-01-27
Automobile Repair Shop Owner

Manufacturer Specific Definitions for P1001

Table of Contents

1. What Does Code P1001 Mean?
2. What are the common causes of code P1001?
3. What are the symptoms of code P1001?
4. How do you troubleshoot code P1001?
5. Codes Related to P1001
6. Get Help with P1001

What Does Code P1001 Mean?

SPECIAL NOTES: Non-professional mechanics should take note that OBD II code P1001 is not a trouble code in the traditional sense. This code merely indicates that there is something wrong in the engine/fuel management system that is preventing the EEC (Electronic Engine Control) module from running, or completing a series of self-diagnostic tests in a period of time that is set by the manufacturer.

Also, take note that while it is sometimes possible to force the EEC module to perform all required tests, actually diagnosing and repairing the cause of code P1001 can generally not be accomplished with cheap, generic code readers. Diagnosing and resolving this code almost always requires the use of dealer-grade diagnostic equipment, above average diagnostic skills, and very often, expert-level knowledge of the affected application. Non-professional mechanics should therefore note that if the cause of this code is not obvious, the better option is always to refer the application to the dealer or other competent repair shop for professional diagnosis and repair.

In addition, be aware that due to the very large number of architectures used by EEC-IV control modules today, this guide cannot provide detailed diagnostic and repair information for code P1001 that will be valid on all applications under all conditions. Thus, the information provided here is intended for general informational purposes only, and should NOT be used in any diagnostic procedure related to code P1001 without making proper reference to the repair manual for the effected application.

Detailed information on forcing the EEC module into a self-test mode can be found here- http://www.troublecodes.net/ford/eectest/  . However, it must be noted that this information does not constitute a cure or remedy for code P1001; the actual cause of the problem must still be investigated and resolved. To this end, this guide will provide some basic, generic diagnostic and repair steps but note that if the actual codes that caused P1001 to set cannot be extracted, the wiser option is to refer the application for professional diagnosis and repair. END OF SPECIAL NOTES.

OBD II fault code P1001 is a manufacturer specific code that is defined by car makers Ford, Mercury, and Lincoln as “Key On/Engine Running Not Able to Complete”, and is set on these applications when the EEC (Electronic Engine Control) module cannot complete a series of self-diagnostic tests that are collectively known as KOER (Key-On-Engine-Running) tests.

In practice, these tests are designed to test the operation and condition of systems such as the MAP/MAF sensor, IAT (Intake Air Temperature) sensor, TPS (Throttle Position) sensor, ECT (Engine Coolant) sensor, Fuel Pressure sensor, and many others including the TCM (Transmission Control Module), as well as the control, monitoring, and feedback circuits of all affected sensors and modules.

This code will set if the required tests cannot be performed in a pre-programmed amount of time, which time period is set by the manufacturer and which further depends on the application and the specific architecture of the EEC module.

NOTE: This guide refers to the EEC-IV iteration of the control system that was used by Ford and related applications up to 2013. Note that “IV” refers to “Version 4” of the engine control system, and that many iterations of this version exist to accommodate all possible engine layouts, cylinder configurations, and other variables between the various engines used by Ford and related manufacturers. For this reason, it is critically important to make sure that the actual EEC module in the application relates to the affected application’s VIN number when diagnosing fault codes that could have caused code P1001 to be set.

What are the common causes of code P1001?

Some common causes of P1001 could include the following, but take note that the possible causes listed here can relate to any system, component, or subsystem that functions within the overall engine/fuel management system(s).

• Damaged, burnt, shorted, disconnected, or corroded wiring and/or connectors
• Blown fuses, and/or defective relays
• Damaged, split, perforated, or dislodged vacuum lines
• Defective sensors, position switches, or actuators. Note that this applies to both vacuum and electrically operated components.
• Failed or failing EEC module. Note that while this is a relatively rare event on most other applications, it is more common on Ford and its related applications. However, EEC failure will almost always be indicated by dedicated EEC related codes.

What are the symptoms of code P1001?

Apart from a stored trouble code and an illuminated warning light, possible symptoms are mostly  model specific, and vary according to the underlying cause(s) of P1001. Refer to then manual for the application for details on the symptoms that are most likely to be present, based on the codes that are present.

How do you troubleshoot code P1001?

NOTE: Since the purpose of the KOER test mode is to monitor the engine and fuel management systems while the engine is running, faults and defects that occur during normal operation of the vehicle will always generate hard, or active, codes. As stated elsewhere, cheap generic code readers cannot always diagnose, or even display some types of codes. However, in many cases, the root cause of code P1001 is a relatively simple issue so before continuing with the diagnostic procedure, perform a thorough inspection of the engine and verify that all engine vacuum hoses are in perfect condition, and that all vacuum hoses are properly attached.

Also, check that all electrical connectors are in good condition, properly engaged, and that there are no visible signs of damage to wiring, and that no wiring is visibly corroded, loose, dangling, or chafed through against the engine or bodywork. Make repairs as required; failure to do this will almost certainly result in misdiagnoses, wasted time, and quite possibly, severe damage to the EEC module.

Step 1

Assuming that all repairs noted above have been made (and that the fault persists) refer to the information here- http://www.troublecodes.net/ford/eectest/ and follow the directions to force the EEC into a self-test mode.

NOTE: This resource is required reading for all who feel confident enough in their ability to diagnose and repair code P1001.

Step 2

Once all fault codes have been extracted, note them down, and refer to the manual for details on the possible relationship(s) between the codes. Note that depending on the nature of the problem there could be many codes present, but the first code should always be investigated first since following codes are often nothing more than a reaction to the first.

Step 3

Be aware that EEC-IV modules are not known for their reliability, and that module failure caused by heat is fairly common in areas with hot climates. Therefore, diagnosing underlying causes of code P1001 is sometimes made easier (and quicker) by testing the various functions of the EEC module itself. Refer to the pin out diagram and table of values below.

Note that while this pin out diagram is of a typical EEC-IV module, it is always a good idea to verify that the EEC connector on the affected application is identical with the diagram shown. Also, note that because the colors of wires can, and do, change between models and applications, the actual color of each wire in the connector cannot be shown. However, the function of the pins in the connector is always the same, regardless of the model or application.

Step 4

If multiple codes are present, start with the first one stored; identify the correct pin on the connector, and verify that the voltage or other value shown on the table for that pin is actually delivering the specified voltage or value. The object of this test is to verify that the relevant circuits in the EEC are working as intended. Repeat this test as often as required to verify that the EEC is not the cause of code P1001.

WARNING: Refer to the manual for the application for details on the exact testing procedure(s), and be sure to follow the directions exactly during these tests to prevent damaging the EEC module.

 Step 5

Once it is certain that all circuits in the EEC are working correctly, continue the diagnostic procedure by thoroughly inspecting all the wiring and connectors that are associated with the first code that was stored. Make repairs as required.

If no visible damage is found, perform reference voltage (if applicable), continuity, resistance, and ground integrity checks on all wiring. Compare all obtained readings to the values stated in the manual, and make repairs or replace wiring as required to ensure that all electrical values fall within the manufacturer’s specifications.

NOTE #1: Sensors form part of the circuits they function in, and as such, all relevant sensors must also be checked for resistance and/or continuity. Replace any sensor that does not conform to specified values.  Be aware though that in some cases, such as replacing throttle actuators, the new throttle actuator must be adapted to the EEC before it will work properly. Be sure to complete all relearning procedures where such a procedure is required before rescanning the system.

NOTE #2: Do not neglect to check vacuum lines and hoses where they occur in a system being checked. Vacuum leaks are a common cause of a variety of codes, which means that repairing a vacuum leak could very well resolve several codes at the same time.

Step 6

It is entirely possible that repairing the first code of several could resolve code P1001, so check if it did by attempting to clear all codes before rescanning the system. However, be sure to follow the directions in the manual exactly to prepare the application for rescanning to avoid a possible misdiagnosis.

Step 7

If the problem persists, repeat Steps 5 and 6 until all codes have been addressed. However, be aware that depending on both the number and nature of the codes, this process could take several hours, and could involve opening complete wiring harness for the purposes of inspecting and testing dozens, and sometimes hundreds of connections and circuits.

Moreover, some tests could require the use of pressure-to-Hertz charts, or other types of reference data such as waveform libraries that may not be readily available. For this reason, it is NOT recommended that non-professional mechanics continue with attempts to diagnose P1001 and its underlying causes beyond performing basic tests as described in Steps 5 & 6. If these steps do not resolve the problem, the wisest possible option by far is to refer the application for professional diagnosis and repair.

Codes Related to P1001

There are no codes that are known to be directly related to P1001-“Key On/Engine Running Not Able to Complete”.

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