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This is one of the most frequent OBD2 trouble codes. Read the full article below to know what it means, how to fix it, and what other codes may show related to it.


DTC Code P1000:

  • OBD-II Monitor Testing Not Complete (Ford) 
  • System Readiness Test Not Complete (Jaguar) 
  • System Diagnosis Incomplete (Kia) 
  • Engine Control Module (ECM) Memory Erased – No Codes Stored (Land Rover) 
  • OBDII Drive Cycle Malfunction (Mazda)


DTC Code P1000 is a manufacturer-specific trouble code, that is, the definition varies from one make or model to another. In a simple and more general term, this code simply means that the OBD-II diagnostic test has not been completed. The causes may vary from one vehicle model to another. For example, this code is triggered in Fords and Jaguars when the Powertrain Control Module (PCM) fails to complete a full diagnosis cycle. 

The monitor test is a series of tests that are required to be completed by the OBD-II system to verify that the vehicle’s emission system is functioning properly. Two major functions are being served by the self-diagnosis test. The first is in detecting when an emission control component has been modified, tampered with, or uninstalled. Thus, it verifies that all components are functioning efficiently. The second is in determining whether or not the OBD-II system has completed all required tests. 

This code in itself is not serious as you only need to complete one or two drive cycles for it to be cleared. In some cases when other trouble codes have been stored alongside, you will be required to reset all other codes before P1000.


The causes of DTC P1000 may vary from one vehicle model to another. This is because this code is manufacturer-specific. In some vehicle makes, such as Ford, Jaguar, and Mazda, this code may be recorded when:

  • The battery is disconnected
  • The Powertrain Control Module (PCM) is disconnected
  • Diagnostic Trouble Codes (DTCs) are deleted without resolving the codes 
  • An OBD-II monitor failure occur before the completion of the drive cycle

In other vehicles, this code may be recorded when:

  • The PCM trouble codes have been cleared with an OBD-II scan tool
  • Power take-off (PTO) circuit is shorted to B+ or VPWR
  • Power take-off (PTO) is on during testing
  • The operating cycles required to remove code P1000 were not completed
  • The time required for the OBD-II system to completely restart may not have elapsed


Although this trouble code is one of the most frequently occurring OBD-II codes, yet it is one of the safest troubles your vehicle may encounter. Under normal circumstances, P1000 poses no threat to the vehicle’s engine or drivability. The only symptom you are certain to encounter is the illumination of the check engine light (CEL). In a nutshell, here are the symptoms that you’re likely to encounter in a vehicle with P1000 trouble;

  • Illumination of the Check Engine Light (CEL), also referred to as Malfunction Indicator Lamp (MIL) 
  • Presence of other trouble codes on rare occasions.


With P1000 being asymptomatic, there is no generally acceptable diagnosis required to resolve this code. Most technicians recommend ignoring the code and it will clear from continuous driving. This may not always work in some cases where the code remains persistent. Hence, you may be required to act to resolve the code. In this case, you only have to complete one or two drive cycles as specified by the vehicles manufacturer.

On the contrary, if the code is stored alongside other OBD-II codes, the diagnosis may not be so direct. Cases like this require an OBD-II scanner to download and read the other codes stored alongside P1000. Having identified the code, or codes as the case may be, you have to first clear the other codes, then clear DTC Code P1000 as a secondary diagnosis.

Before you begin the diagnosis, you need to have enough fuel in your tank — at least a quarter of the full tank — along with a fully charged battery and an OBD-II scanner. Equipped with these, follow the procedures below to complete a drive cycle:

  • First, use the OBD-II scanner to download and read the freeze frame data and see if other codes are stored
  • If other codes are stored, download and read the data specific to the other stored codes. Check other codes on our DTC codes page for detailed information
  • Having cleared the other codes, begin the drive cycle by first leaving the vehicle engine to cool to almost the same temperature as the environment. This can be achieved by allowing the vehicle to rest for about 8 hours
  • Then start the vehicle and leave it idle. While idle, observe the operation of the heater, defrosters, and headlights 
  • Next, take the vehicle for a test drive, running at a speed of 25 mph for about 15-20 minutes. During the drive, increase the speed to about 40 mph once or twice before coming to a complete stop
  • Then increase the speed to about 55-60 mph, maintain this speed for at least 5 miles. You should activate cruise control if you have the option
  • Allow your vehicle to coast and gradually reduce the speed as much as possible. In case of manual transition, avoid shifting gears as long as you can
  • Repeat step 5 for another 15-20 minutes. Then Park the vehicle and allow it to be idle for 1-2 minutes before you turn off the ignition

Common mistakes

Being a manufacturer-specific OBD-II code, you should ensure that you read the definition as applicable to your vehicle model when dealing with this trouble code. Although there is a similarity between the various definitions of this code, they may relate to different systems for different manufacturers.

How serious is this?

In terms of severity, DTC Code P1000 in itself usually has no side effects. This is because this code does not have any effect on the vehicle’s engine or drivability. In a more factual sense, this code can resolve itself automatically without any intervention. Hence, it is safe to drive a vehicle showing P1000 without risking the health of the vehicle or pose the vehicle to other more serious issues.

However, if the vehicle records other DTC codes alongside this code, then you should consider fixing the codes with immediate effect. 

What repairs can fix the code?

repair manuals

As stated above, the code will clear off from continuous driving if you chose to ignore it. Conversely, you may choose to act on this code to clear it quickly. In that case, it is important to note that there is no universal or generally accepted repair for this code. Nevertheless, most vehicles, such as Ford and Jaguar, usually require you to complete one or two drive cycles to resolve this code. In addition to the procedures given above, you may consult your vehicle’s service manual to know how you can complete the drive cycles for a particular vehicle.

If the code is persistent in a particular vehicle, using a factory-specific software may be required. Using such software allows you to manually command a full series of readiness checks. Once these checks are completed in the vehicle, the code should be cleared. Lastly, ensure that the battery and the OBD-II systems are securely connected. 

Related codes

  • P1299 – Cylinder Head Over Temperature Protection Active
  • P1101 – Mass Air Flow (MAF) Sensor Out of Self-Test Range
  • P1405 – Differential Pressure Feedback Sensor Upstream Hose Off or Plugged
  • P1001 – Key on Engine Running (KOER) Not Able to Complete, KOER Aborted
  • P0171 – System Too Lean (Bank 1)
  • P0174 – System Too Lean (Bank 2)
  • P1639 – Vehicle ID Block Corrupted or Not Programmed


DTC P1000 in itself is not a serious code unless other OBD-II codes are stored together with it. In such cases diagnosing all other codes should be a priority before actually resolving P1000. It is however important to note that different vehicle models have different approaches and this can be found in their service manual. As a parting note, inspect the battery and the PCM connections and ensure they are securely connected as they may contribute to the persistent presence of this code.