Ford F150 Pickup. Manual - part 1407

3. Input signal to PCM is then used to calculate time between CKP edges and also crankshaft rotational 

velocity and acceleration. By comparing accelerations of each cylinder event, power loss of each cylinder 
is determined. When power loss of a particular cylinder is sufficiently less than a calibrated value and 
other criteria is met, then suspect cylinder is determined to have misfired.  

4. Misfire types are as follows: 

Misfire Type A 
 
Upon detection of a Misfire Type A (200 revolutions) which would cause catalyst damage, MIL 
will blink once per second during actual misfire, and a DTC will be stored. 

Misfire Type B 
 
Upon detection of a Misfire Type B (1000 revolutions) which will exceed emissions threshold or 
cause a vehicle to fail an inspection and maintenance tailpipe emissions test, MIL will illuminate 
and a DTC will be stored.  

The DTC associated with multiple cylinder misfire for a Type A or Type B misfire is DTC P0300. DTCs 
associated with an individual cylinder misfire for a Type A or Type B misfire are; DTCs P0301, P0302, 
P0303, P0304, P0305, P0306, P0307, P0308, P0309 and P0310. 

SECONDARY AIR INJECTION SYSTEM MONITOR - ELECTRIC SECONDARY AIR INJECTION 
PUMP SYSTEM 

Secondary Air Injection (AIR) system monitor is an on-board strategy designed to monitor proper function of 
secondary air injection system. AIR monitor for electric secondary air injection pump system consists of 2 
monitor circuits: an AIR circuit to diagnose concerns with primary circuit side of Solid State Relay (SSR), and 
an AIR Monitor circuit to diagnose concerns with secondary circuit side of SSR. A functional check is also 
performed that tests ability of AIR system to inject air into exhaust. Functional check relies upon HO2S sensor 
feedback to determine presence of air flow. The monitor is enabled during AIR system operation and only after 
certain base engine conditions are first satisfied. Input is required from ECT, IAT, and CKP sensors and HO2S 
monitor test must also have passed without a fault detection to enable AIR monitor. AIR monitor is also 
activated during KOER self-test.  

1. The AIR circuit is normally held high through AIR bypass solenoid and SSR when output driver is off. 

Therefore a low AIR circuit indicates a driver is always on and a high circuit indicates an open in PCM. 
DTC P0412 is associated with this test.  

2. The AIR Monitor circuit is held low by resistance path through AIR pump when pump is off. If AIR 

monitor circuit is high, there is either an open circuit to PCM from pump, or there is power supplied to 
AIR Pump. If AIR monitor is low when pump is commanded ON, there is either an open circuit from 
SSR or SSR has failed to supply power to pump. DTCs P1413 and P1414 are associated with this test.  

3. The functional check may be done in 2 parts: at start-up when AIR pump is normally commanded ON, or 

during a hot idle if start-up test was not able to be performed. The flow test relies upon HO2S to detect 
presence of additional air in exhaust when introduced by secondary air injection system. DTC P0411 is 
associated with this test.  

4. MIL is activated after one of the above tests fail on 2 consecutive drive cycles.  

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE Self-Diagnostics - CNG, Flex-Fuel & Gasoline

  

THERMOSTAT MONITOR 

Thermostat Monitor is designed to verify proper thermostat operation. This monitor only applies to certain 
applications beginning with the 2000 model year and replaces "Insufficient temperature for closed-loop 
test" (DTC P0125). This monitor will be executed once per drive cycle and has a monitor run duration of 300-
800 seconds. If a malfunction is indicated by thermostat monitor a DTC P0125 will be set and MIL will be 
illuminated. The monitor checks Engine Coolant Temperature (ECT) or Cylinder Head Temperature (CHT) 
sensor to warm up in a predictable manner when engine is generating sufficient heat. A timer is started while 
engine is at moderate load and vehicle speed is above a calibrated limit. Target timer value is based on ambient 
air temperature at start-up. If timer exceeds the target time and ECT/CHT has not warmed up to target 
temperature, a malfunction is indicated. The test runs if start-up intake air temperature from IAT sensor is at, or 
below target temperature. A 2-hour engine off soak time is required to erase a pending or confirmed DTC. This 
soak time feature prevents false-passes of monitor when the engine coolant temperature rises after engine is 
turned off during a short engine off soak period. The target temperature will be calibrated to thermostat 
regulating temperature minus 20°F (11°C). For a typical 195°F (90°C) thermostat, warm-up temperature would 
be calibrated to 175°F (79°C). For the 2003 model year, some vehicle calibrations may lower the target 
temperature when ambient temperature is below 50°F (10°C). This lower target temperature is for vehicles that 
do not warm-up to the thermostat regulating temperature when ambient temperature is 20-50°F (-7-10°C). 

Inputs 
 
ECT or CHT, IAT, engine LOAD (from MAF sensor) and vehicle speed input. Typical monitor entry 
conditions are as follows: 

z

Vehicle speed more than 15 MPH.  

z

Intake air temperature at start-up is between 20°F (-7°C) and target thermostat temperature.  

z

Engine load more than 30 percent.  

z

Engine off (soak) time more than 2 hours.  

Output 
 
Malfunction Indicator Lamp (MIL)  

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE Self-Diagnostics - CNG, Flex-Fuel & Gasoline

  

PROGRAMMING PCM 

POWERTRAIN CONTROL MODULE RESET 

Description 

All OBD-II scan tools support Powertrain Control Module (PCM) reset. The PCM Reset allows the scan tool to 
command the PCM to clear all emission-related diagnostic information. When resetting the PCM, a DTC P1000 
will be stored in the PCM until all the OBD-II system monitors or components have been tested to satisfy a 
drive cycle, without any other faults occurring. See DRIVE CYCLES. 

The following events occur when a PCM reset is performed:  

z

Clears the number of Diagnostic Trouble Codes (DTCs).  

z

Clears the DTCs.  

z

Clears the freeze frame data.  

z

Clears diagnostic monitoring test results.  

z

Resets status of the OBD-II system monitors.  

z

Sets DTC P1000.  

Resetting Keep Alive Memory (KAM) 

Resetting Keep Alive Memory will return PCM memory to its default setting. Adaptive learning contents such 
as idle speed, refueling event, and fuel trim are included. A PCM Reset (described above) is also part of a KAM 
Reset. Both can be useful in post repair retest. 

After Keep Alive Memory has been reset, the vehicle may exhibit certain driveability concerns. It will be 
necessary to drive the vehicle to allow the PCM to relearn values for optimum driveability and performance. 

If an error message is received or the scan tool does not support this function, disconnecting the battery ground 
cable for a minimum of 5 minutes may be used as an alternative procedure. 

FLASH ELECTRICALLY ERASEABLE PROGRAMMABLE READ ONLY MEMORY (FLASH 
EEPROM) 

Description 

Flash Electrically Eraseable Programmable Read Only Memory (EEPROM) is contained in an Integrated 
Circuit (IC) internal to the PCM. The EEPROM contains the vehicle strategy including calibration information 
specific to the vehicle and is capable of being reprogrammed or reflashed repeatedly. 

As part of the calibration there is an area referred to as the Vehicle Identification (VID) block. The VID block 

NOTE:

This function may not be supported by all scan tools. Refer to scan tool 
manufacturer's manual instruction.

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE Self-Diagnostics - CNG, Flex-Fuel & Gasoline

  

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE Self-Diagnostics - CNG, Flex-Fuel & Gasoline

  

must be programmed when replacing the PCM as described under Programming the VID Block for a 
Replacement PCM. Failure to perform this procedure may generate fault codes: P1635, P1639, VID Block not 
programmed or is corrupt. The VID block in an existing PCM can also be tailored to accommodate various 
hardware/parameter changes made to the vehicle since production. Failure to perform this procedure properly 
may generate fault code: P1635, Tire/Axle Ratio out of Acceptable Range is one of the main causes for code: 
P1639. This is described under Making Changes to the VID Block and also under Making Changes to the PCM 
Calibration. The VID block contains many items used by the strategy for a variety of functions. Some of these 
items include the VIN number, octane adjust, fuel octane, fuel type, vehicle speed limit, tire size, axle ratio, the 
presence of speed control and four wheel drive electronic shift on the fly versus manual shift on the fly. Only 
items applicable to vehicle hardware and supported by the VID block will be displayed on the scan tool. 

When changing items in the VID block, the strategy will place range limits on certain items such as tire and 
axle ratio. The VID block is also limited to the number of times to be reconfigured. When this limit is reached, 
the scan tool will display a message indicating the need to flash the PCM again to reset the VID block. 

The following procedures use the Worldwide Diagnostic System (WDS) for reprogramming:  

z

PROGRAMMING VID BLOCK FOR REPLACEMENT PCM  

z

MAKING CHANGES TO THE VID BLOCK  

z

MAKING CHANGES TO THE PCM CALIBRATION  

Reprogramming can be performed by a local Ford dealer for any non Ford facility. There are other Enhanced 
Scan Tools that may have reprogramming capabilities available. Refer to the manufacturers users manual for 
details. 

Programming VID Block For Replacement PCM 

A new PCM will contain the latest strategy and calibration level for a particular vehicle. However, the VID 
block will be blank and will need programming. There are 2 procedures available. The first is an automatic data 
transfer from the old PCM to the new PCM and the second is manual data entry into the new PCM. 

Automatic data transfer will be performed if the old PCM is capable of communicating. This is done by the use 
of a scan tool to retrieve data from the old PCM before removing it from the vehicle. The stored data can now 
be downloaded to the new PCM after it has been replaced. 

Manual data entry must be performed if the old module is damaged and/or incapable of communicating. 
Remove and replace the old PCM. Using a compatible Scan Tool select and execute MODULE/PARAMETER 
REPROGRAMMING referring to the manufacturers users manual. Important, make certain that all parameters 
are included. Failure to properly program Tire Size in revolutions per mile, (rev/mile equals 63,360 divided by 
the tire circumference in inches) Axle Ratio, 4x4/4x2, and/or Manual/Electronic shift on the fly (MSOF/ESOF) 
may result in codes: P1635, P1639. You may be instructed to contact the AS BUILT data center for the 
information needed to manually update the VID block with the scan tool. Contact the center only if the old 
PCM cannot be used or the data is corrupt. For Ford Lincoln Mercury technician's, contact your National 
Hotline or the Professional Technician Society (PTS) web site for AS BUILT data. Non Ford technicians, use 
the Fed World web site at fedworld.gov. Select AUTO SERVICE INFORMATION and search for 
CALIBRATIONS or VEHICLE CALIBRATIONS then specify vehicle manufacturer, model name and model 
year as required. 

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE Self-Diagnostics - CNG, Flex-Fuel & Gasoline