P1000 – OBDII Monitor Testing Not Complete (Ford, Jaguar, Lincoln)

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By Reinier (Contact Me)
Last Updated 2016-11-14
Automobile Repair Shop Owner
CodeFault LocationProbable Cause
P1000 P1000 – OBDII Monitor Testing Not Complete (Ford, Jaguar, Lincoln)
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Disconnected battery, insufficient time to reset

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Manufacturer Specific Definitions for P1000

MakeFault Location
BmwVVT control circuit, solenoid loss, bank 1
DodgeIgnition coil, 5 -primary circuit range/performance
FordOn Board Diagnostic System Readiness Test Not Complete
FreightlinerIgnition coil, 5 -primary circuit range/performance
JaguarEngine control module (ECM) - internal error
KiaSystem diagnosis incomplete
Land RoverEngine control module (ECM) memory erased – no codes stored
LincolnSystem readiness test not complete
MazdaOBD-11 monitor testing not complete
Mercedes-BenzTransmission shift lever control module- defective
MercurySystem readiness test not complete
MiniSecondary AIR Delivery
VolvoEngine control module (ECM) – circuit malfunction

Table of Contents

  1. What Does Code P1000 Mean?
  2. What are the common causes of code P1000?
  3. What are the symptoms of code P1000?
  4. How do you troubleshoot code P1000?
  5. Codes Related to P1000
  6. Get Help with P1000

What Does Code P1000 Mean?

OBD II code P1000 is generally defined as “OBDII Monitor Testing Not Complete”, and is set either when the OBD II system has not completed a full self-diagnostic cycle, or when there are conditions present that prevent the system from running self-diagnostic tests. Note that while code P1000 is a manufacturer-specific code, the actual definition assigned to the code varies somewhat between manufacturers. Below are some examples of different definitions for this code-

  • P1000 – Jaguar: “Engine control module (ECM) – internal error”
  • P1000 – Land Rover: “Engine control module (ECM) memory erased – no codes stored”
  • P1000- Mazda: “OBDII Drive Cycle Malfunction”

Monitor testing” refers to the battery of tests the OBD II system needs to complete to confirm that the emission control system on the application is fully functional. However, when dealing with P1000 it is important to define the definition: in automotive diagnostics parlance, “monitor” refers to the circuits involved in testing each function, component, or sub-system of the emission control system.

The primary function of the self-diagnostic capability is two-fold:

  • To detect if any emission control system components have been tampered with, removed, bypassed, modified, or altered in any way to ensure that all components are present and are working as designed on the one hand, and

  • to determine whether the vehicles’ OBD II system has completed all required tests, on the other.

Note that code P1000 does not identify, or indicate faults per se; all its presence indicates is that the self-diagnostic procedure is not complete, or cannot be completed. Also, note that some functions are continuously monitored by the OBD II system (while the vehicle is driven) while others require very specific conditions to be met before a test can be run, or completed by the OBD II system.

The latter group of tests is commonly referred to as “non-continuous monitors”. This group of tests is fundamentally different from continuous monitors, in the sense that environmental factors often determine whether a test can be run or not. One example of this is a long spell of cold weather that can influence the working of the EVAP system especially on some Ford products, although cold weather combined with high altitudes can influence other makes as well.

Readiness monitors explained

NOTE: Due to the differences in the design specifics of emission control systems of different applications, it is not possible to provide exact, specific information for all applications. The information below is therefore not exhaustive, or definitive, and it is presented here for general informational purposes only. Always refer to the relevant manual for the application being worked on for detailed information pertaining to code P1000.

Nonetheless, the short description of various types of monitors below should suffice to provide a general sense of the types of self-diagnostic tests performed by a typical OBD II system on a modern vehicle.

Continuous monitors:

The tests below are carried out on a continuous basis as the vehicle is driven, since failures or defects in these systems have a direct bearing on combustion, and hence emissions-

  • Misfire detection
  • Fuel system

Both these tests involve comprehensive checking and monitoring of all components in the systems.

Non-continuous monitors

NOTE: Due to the major differences in the operating principles of gasoline and diesel engines, non-continuous monitors are different for each type of engine.

Non-continuous monitors for gasoline engines:

  • Catalytic converter function
  • Heated catalyst operation
  • Leak detection in the EVAP system
  • Secondary air injection system function
  • Oxygen sensor function, which includes checking the functioning of the heated element in the sensor
  • Exhaust gas recirculation system function
  • VVT/VCT system operation

Non-continuous monitors for diesel engines:

  • NMHC (Non-methane Hydrocarbon) catalyst function
  • SCR (Selective Catalytic Reduction) effectiveness
  • Forced induction pressure
  • Exhaust gas temperature
  • DPF (Diesel Particulate Filter) condition or state
  • Exhaust gas recirculation system function
  • VVT/VCS system operation

What are the common causes of code P1000?

In the majority of cases, P1000 is set either when the battery is disconnected, or when not sufficient time has passed for the OBD II system to reset fully after clearing other codes without having resolved them.

Note however that in many cases, the OBD II system requires a full drive cycle (or two cycles in some cases) to fully reset even after emission control-related trouble codes had been resolved successfully. It is also possible to find code P1000 on brand new vehicles that have not yet completed the required drive cycle(s) to clear P1000 automatically.

What are the symptoms of code P1000?

Code P1000 will rarely exhibit symptoms other than a stored code and perhaps an illuminated warning light. However, where codes or conditions exist that prevent the OBD system from running or completing self-diagnostic tests, those codes or conditions might produce drivability issues and/or other symptoms, and they must therefore be resolved before attempting to clear P1000. Note that P1000 can generally not be cleared before codes and/and conditions that brought up P1000 are resolved.

How do you troubleshoot code P1000?

Since P1000 is not a fault code per se, there are no specific or even generalized diagnostic and repair procedures for it. However, in the vast majority of cases where P1000 is present, resolving it could be as simple as completing a drive cycle as per the manufacturer’s definition of a drive cycle. Consult the manual for the application being worked on for detailed information of what constitutes a drive cycle for that particular application.

Nonetheless, some cures require real work, time, and trouble and while it is not possible to list all possible cures here, the table below provides a general overview of what might be required to resolve P1000. Note that this table lists possible causes of P1000 on both gasoline and diesel engines. Also, take particular note of the fact that the table below merely lists the parameters used by the OBD II system when checking each component or system during self-diagnostic resting. The actual value, or relevance of each parameter to code P1000 listed here must be researched before drawing any conclusions as to the most probable cause of P1000.


Parameters Monitored

Fuel system

Fuel system pressure control

Injection quantity

Injection timing

Feedback control


Detection of continuous, or random misfires

Determination of % of misfires / 1000 engine cycles (2013 and later engines)


Low flow

High flow

Slow response

EGR cooler operation

EGR catalyst performance

Feedback control

Boost pressure

Detection of under-boost/over-boost conditions

Slow response

Monitoring of charge air temperature

Feedback control

NMHC catalyst

Conversion efficiency

DPF heating

SCR feedgas (e.g., NO2)

Provide post DPF NMHC clean-up

Provide ammonia clean-up

Catalyst aging

SCR NOx catalyst

Conversion efficiency:

SCR reductant delivery performance

Tank level, fuel quality, and injection feedback control

Catalyst aging

NOx adsorber

NOx absorber capability

Desorption function

Fuel delivery

Feedback control


Filtering performance

Regeneration frequency

NMHC conversion

Incomplete regeneration

Missing substrate

Active regeneration

Fuel delivery

Feedback control

Exhaust gas sensors

For air-fuel ratio and NOx sensors:


Circuit faults,

Feedback, and monitoring capability

Other exhaust gas sensors

Sensor heater function

Sensor heater circuit faults


Target error

Slow response

Cooling system/



ECT sensor circuit faults

ECT sensor circuit out-of-range

ECT sensor circuit rationality faults

System integrity

Comprehensive component monitoring

Cold start emission reduction strategy

Other emission control system monitoring

There are no “related” codes, except in the sense that the presence of one or more other codes and/or fault conditions along with P1000 could prevent the execution of self-diagnostic tests.

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