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Severity: Minor Code type: Manufacturer-specific (Ford)

Ford P1000 Code: OBD-II Monitor Testing Not Complete

Ford's computer hasn't finished all its self-tests yet. It's a status message, not a fault.

At a glance

Severity: 1/5 – Minor1/5

Severity: Minor

Meaning
OBD-II Monitor Testing Not Complete
System
ECU & Outputs · Powertrain
Safe to drive?
Yes, short term
Typical repair cost
$0–$400
DIY difficulty
Very easy

On Ford vehicles, P1000 is an information code rather than a failure. The PCM runs a set of self-tests called readiness monitors (catalyst, EVAP, oxygen sensors and their heaters, EGR and others) that only execute under specific driving conditions. After the battery is disconnected, codes are cleared, or the PCM is replaced or reprogrammed, those results are wiped and P1000 is stored until every monitor has run at least once. It does not turn on the check engine light and goes away by itself once the car has been driven enough.

Can I keep driving? Drive normally; P1000 doesn't affect how the car runs. The only practical impact is that the vehicle may not be accepted for an emissions test until enough monitors have completed.

Try this first – 5-minute fix

  1. Make sure P1000 is the only code Scan for other stored or pending codes. If P1000 is alone and the check engine light is off, there's nothing to repair.
  2. Drive a mix of city and highway Over a few days, include several miles of steady cruising at 40-60 mph, some gentle decelerations without braking, and a few minutes of idling. This gives the catalyst, oxygen sensor and EGR monitors the conditions they need.
  3. Set up the EVAP monitor Keep the tank between about 1/4 and 3/4 full and let the car sit overnight, ideally outside at moderate temperatures. Start it cold the next morning and drive normally; the EVAP test runs during that first drive.
  4. Don't clear codes or disconnect the battery Clearing codes or unhooking the battery resets every monitor and starts the process over. Let the car finish, then confirm readiness with a scan tool before the emissions test.

How to read P1000

How to read P1000P11203004
  1. P Powertrain
  2. 1 Manufacturer-specific
  3. 0 Fuel/air & emissions (aux.)
  4. 00 Specific fault

Symptoms

  • No drivability symptoms and no check engine light
  • Code reader shows P1000 after battery replacement or clearing codes
  • Readiness status shows one or more monitors as 'not ready' or 'incomplete'
  • Emissions test station reports the vehicle as not ready

Possible causes

Ranked by how often each cause is behind this code (editorial estimate).

  1. Battery was disconnected, replaced or went flat, wiping the PCM's stored test results 40%
  2. Trouble codes were recently cleared with a scan tool 30%
  3. Only short trips driven, so the conditions for some monitors (especially EVAP and catalyst) never occurred 15%
  4. PCM was replaced or reprogrammed 8%
  5. An underlying fault (for example a thermostat stuck open or a pending code) is stopping a monitor from running 7%

Diagnosis step by step

Diagnostic flow: P10001Check for other codes, includingpending ones2Look at the readiness monitor list3Confirm the engine reaches fulltemperature4Check that the PCM keeps its memory5Recheck readiness after a few days

  1. Check for other codes, including pending ones

    Read all stored and pending codes. If another code is present, fix that first; a pending fault can stop the related monitors from ever completing, and P1000 will then stay put.

    Tools: OBD-II scanner

  2. Look at the readiness monitor list

    Most scan tools show each monitor as ready or not ready. Note which ones are still incomplete, because each has its own driving conditions; EVAP and catalyst are usually the last to finish.

    Tools: OBD-II scanner

  3. Confirm the engine reaches full temperature

    With live data, check that coolant temperature climbs to roughly 190-220 °F after 15 minutes of driving. An engine that stays cold, often because of a thermostat stuck open, can block several monitors and may also set P0128.

    Tools: OBD-II scanner

  4. Check that the PCM keeps its memory

    If P1000 comes back every time the car sits, the PCM may be losing its keep-alive power. Check battery condition, clean the terminals, and check the fuse that supplies the PCM's constant power.

    Tools: Multimeter, Pliers

  5. Recheck readiness after a few days

    After several days of mixed driving, read the readiness status again. Once all supported monitors report ready, P1000 disappears on its own without being cleared.

    Tools: OBD-II scanner

Where the parts are

Charging system and control modules – P10001234567
Charging system and control modules
  1. 1Battery
  2. 2Alternator
  3. 3Engine computer (ECM)
  4. 4CAN bus
  5. 5Transmission
  6. 6Wheel speed sensor
  7. 7High-voltage battery

Repair options & costs

RepairDIY?Estimated cost
Normal driving to complete monitors Yes $0
Shop-performed drive cycle and readiness check No $50–$150
Fix battery or PCM keep-alive power problem Yes $20–$300
Repair underlying fault blocking a monitor (e.g. thermostat) No $150–$400

Rough US estimates for parts and labor; shop rates vary by region. Not a quote.

Notes by brand

Mazda

Many Mazda models, which share engine-management strategy with Ford, use P1000 with the same meaning: monitor testing not yet complete.

Emissions / smog test impact

Depends

US emissions programs following EPA guidance generally allow one incomplete monitor on 2001 and newer vehicles and two on 1996-2000 models; more than that and the car is turned away as 'not ready' rather than failed. Drive it for a few days after battery work before testing.

Frequently asked questions

Do I need to fix anything for P1000?

Usually not. It simply means the PCM hasn't finished its self-tests since its memory was cleared. Normal driving over a few days completes the monitors and the code goes away by itself.

Why won't P1000 go away?

Either the car only does short trips, the fuel level or temperature keeps preventing the EVAP test, or another fault is blocking a monitor. Check for pending codes and make sure the engine reaches full operating temperature.

Can I pass a smog check with P1000?

Only if enough monitors are complete. P1000 itself doesn't fail the test, but too many incomplete monitors will get the car rejected as not ready, so drive it normally for several days first.

Why did P1000 show up after I replaced my battery?

Disconnecting the battery erases the PCM's stored monitor results and adaptive values. The PCM sets P1000 to show it's starting its self-tests from scratch.

Sources