Ford Falcon. Manual — part 201

303-14-18

Powertrain Control Management

303-14-18

DESCRIPTION AND OPERATION (Continued)

nitrogen oxide (NOX) gasses, while providing

Module Programming

excellent fuel economy, optimal power and

performance. The system regulates emissions and

Special Tool(s)

fuel economy by controlling the air-fuel ratio at the

Worldwide Diagnostic System

optimum level during different driving conditions.

(WDS)

Within the closed loop system, deviations from the

—

optimal air-fuel ratio are measured. The PCM

monitors the signal from the HEGO sensor, then

adjusts fuel-air mixture to maintain the correct ratio.
The principle is based on measuring the residual

oxygen content in the exhaust with a HEGO sensor.

The oxygen content of the exhaust is a measure of

Principles of Operation

the air-fuel ratio being provided to the engine. Where

PCM modules must be programmed as part of the

the air-fuel ratio deviates from the stoichiometric point

repair procedure. If this procedure is not followed the

of 14.64:1, the sensor voltage output changes

module will not function correctly and may set a

sharply. The PCM evaluates the change and adjusts

number of DTCs, including P1639, which indicate that

the injector pulse width to maintain the air fuel ratio

some necessary data has not been programmed into

within the stoichiometric point. In Closed Loop Mode,

the module.

the air-fuel ratio is kept at the optimum for all driving

PCMs should not be exchanged between vehicles. In

conditions.

most cases the parameter values or settings are

This precise control of the fuel-air ratio allows a

unique to that vehicle, and if not set correctly will

catalytic converter to be used in the exhaust system

cause malfunctions or faults.

to burn-up the harmful particles and maintain the

WDS will automatically attempt to retrieve the module

lowest exhaust emissions.

configuration information from all modules, and from a

After the HEGO has reached operating temperature,

backup location in the PCM when the vehicle ID is

the PCM selects Closed Loop Mode during closed

carried out. If the module and the PCM do not contain

throttle or part throttle operation.

correct information the diagnostic tool will display a list

Closed Throttle Mode

of items that you will need to manually configure. The

diagnostic tool will program the module based on the

Closed Throttle Mode occurs whenever there is no

data you enter.

demand on the throttle. This occurs during idle,

There are three different methods that are used for

coasting and deceleration. The PCM is able to detect

module programming:

a closed throttle condition by monitoring the signal

from the Throttle Position Sensor (TP) <TPS>.

programmable module installation (PMI)

The PCM controls idle speed, injector pulse width and

module reprogramming

ignition timing in Closed Throttle Mode to maintain the

programmable parameters

correct air-fuel ratio.

Some modules do not support all three methods.

Under periods of prolonged idle, the PCM will exit

Programmable Module Installation (PMI)

closed loop mode and hold the mixture slightly richer

than the stoichiometric point to enhance idle quality.

The programmable module installation (PMI) method

During deceleration at engine speeds above

is used when a new PCM module is installed on the

approximately 2,000 RPM, the injectors are shut off.

vehicle. The diagnostic tool automatically obtains any

At engine speeds below 2,000 RPM, the fuel injectors available module option content information for the old

are re-enabled.

PCM during the vehicle ID routine that runs when the

diagnostic tool is initially connected to the vehicle. It is

Powertrain Control Hardware

important that you connect WDS to the vehicle and

allow it to identify the vehicle and obtain configuration

Powertrain Control Module

data prior to removing the old PCM.

The centre of the PCM system is a microprocessor

Module Programming

controlled Powertrain Control Module (PCM).

Depending on model, the PCM has 92 or 122

Calibration update is used to install a new calibration

electrical connector pins through which it receives

and strategy into a module. The updates are usually

input from sensors and other electronic components.

issued to fix a concern in the module software and

Based on information received and programmed into

would normally be addressed by another technical

its memory, the PCM generates output signals to

service bulletin (TSB).

control the engine and transmission through various

relays, solenoids and actuators.

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303-14-19

Powertrain Control Management

303-14-19

DESCRIPTION AND OPERATION (Continued)

Keep Alive Power (KAPWR) when the ignition key is

Vehicle Identification (VID) Block

in the OFF position so that this information is not lost.

The PCMs contain a memory area called a vehicle

KAPWR is routed through a fuse, situated in the

identification (VID) block. The VID block is used to

instrument panel.

store powertrain configuration information.

If the PCM power supply is interrupted then the PCM

The PCM VID block contains the factory settings for

may lose the "Keep Alive Memory" data. The KAM

the configurable modules unless the PCM is flashed

data retention time for the PCM depends on the

with a new calibration in which case some PCM

module temperature during the period without power

parameters may be modified.

(e.g. battery disconnected).

General Procedures

Vehicle Reference Voltage
Vehicle Reference Voltage (VREF) is a positive 5.0

General Procedures

Volt output from the PCM used by 3-wire sensors.

Tire Size and Axle Ratio

Signal Return

Using the WDS, select Module Configuration and

The Signal Return (SIGRTN) is a dedicated ground

Programming, then follow the screen prompts.

circuit used by engine sensors.

Tire Size, Axle Ratio and Option Index

Power Ground

Feature

Falcon

Power Ground (PWRGND) is an electric ground

Tire Size

215/60R16

return for the Powertrain Control Module (PCM).

225/50R17
245/40R18

Power Supply

235/45R17

The PCM’s power relay voltage supply (VPWR) is

255/60R16

controlled by the PCM’s power sustain (PWRSTN)

output circuit. The PWRSTN output turns on

215/55R16

immediately when the ignition is “ON” and maintains

Axle Ratio

3.23

power to the PCM power relay for a further 1 second

3.45

after key-off. This key-off delay enables the PCM to

position the ETC throttle plate close during engine

Speed Control

Not Present

shut down.

Present

Speed Source

ABS Only

Connections

Other

PCM Pin B9

….. . . . . . IGNSNS

Traction Control

PCM Pin B37

….. . . . . … PWRSTN

PCM Pin B34, B36

. . . . . … VPWR

Power and Ground Signals

Failure Mode

Vehicle Power

If the PCM does not appear to turn on (no engine

TURN-ON

crank and no PRNDL display when T-bar is moved),

When the ignition switch is turned to the START or

ascertain that the PCM is being correctly powered up.

RUN positions, positive battery voltage (B+) is applied Failure in the IGNSNS and PWRSTN circuit or wiring

to the PCM’s IGNSNS input. The PCM’s PWRSTN

circuit will result in no power to the PCM.

output grounds the VPWR relay. Since the other end

Testing

of the VPWR relay coil is wired to B+, this energises

the coil and closes the contacts of the PCM power

Refer to wiring diagrams 303-14-00/01 (I6) and

relay. This supplies VPWR to the PCM, turning it on.

303-14-00/02 (V8).

TURN-OFF

1. Ensure that the vehicle ignition system and the

When the ignition switch is turned to the OFF or ACC

instrument cluster is working correctly by

positions, the PCM’s IGNSNS input reads 0V. The

observing the warning lamps on the instrument

PCM turns off the injectors and commands the

cluster at the ignition “RUN” position.

electronic throttle to the closed position.

2. Remove the PCM power relay.

Approximately 1 second later, the PWRSTN output

3. While the ignition is in the RUN position, measure

turns off and de-energises the PCM power relay. This

the voltage of the 4 relay pin and ground. Ensure

turns off VPWR to the PCM.

that the contact pin 361A and the relay coil pin

513 measure 12V. Rectify wiring if required.

Keep Alive Memory
The PCM stores some information in Keep Alive

Memory (KAM). The KAM remains powered through

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303-14-20

Powertrain Control Management

303-14-20

DESCRIPTION AND OPERATION (Continued)

4. Measure the voltage of the relay coil pin 175E to

CKP Sensor, I6 Engine

the battery 12V. If this measures 12V, replace the

relay with a known good unit and ensure that the

relay clicks as it is inserted into the relay socket. If

12V is not measured, remove the PCM and probe

the IGNSNS pin for 12V (ensure key is in the

“RUN” position) and check the wiring continuity

between PWRSTN and the relay coil pin 175E.

Rectify wiring if required.

5. Reinstall the PCM power relay.
6. To confirm that the relay circuitry is operational,

ground the PWRSTN pin and ensure that 12 V is

present at the VPWR pins at the PCM.

7. Turn the key to the “OFF” position.
8. Plug the wiring harness to the PCM.

The CKP signal is produced by an Inductive Pulse

9. Start

the

vehicle.

Generator. Its main components are a reluctor

If the PCM is still non-functional, replace the PCM.

(toothed wheel on the harmonic balancer) and a

pick-up coil. When the engine rotates, the toothed

Inputs

wheel passes the coil pick-up. The strength of the

magnetic field changes from strong to weak, and

Crankshaft Position Sensor (CKP)

vice-versa, as the teeth rotate past the pick-up coil.

The amplitude and frequency of the CKP signal is

The Crankshaft Position (CKP) sensor is a magnetic

proportional to engine speed. As engine speed

transducer mounted on the front timing cover. A

increases, so does the voltage amplitude.

reluctor (tooth wheel) is mounted on the front of the

crankshaft internal to the engine. The CKP is the

CKP Sensor, V8 Engine

primary sensor for ignition timing information used by

the powertrain control module (PCM).
The reluctor, or trigger wheel, has a total of 35 teeth,

spaced 10 degrees apart with one empty space for a

missing tooth. By monitoring the trigger wheel, the

CKP indicates crankshaft position and speed

information to the PCM.
The PCM uses the CKP signal and the Camshaft

Position Sensor (Cylinder Identification) (CMP) <CID>

signal to determine the position of piston 1 within the

cycle. From this, the PCM calculates spark and fuel

injection timing.
The CKP signal converts the crankshaft position to an

electrical signal as shown below. The analogue AC

voltage CKP signal is converted to a digital PIP signal;

The reluctor has a missing tooth positioned before

this signal is used internally by the Powertrain Control

cylinder No. 1 reaches TDC. The PCM keeps count of

Module (PCM), every rising edge signals that the

the teeth as they pass the pick-up, using the missing

crankshaft is 10

° before TDC for a particular cylinder

tooth as a reference point. The PCM can then

s compression stroke.

calculate the exact crankshaft position at any time. As

the crankshaft rotates twice between each combustion

stroke, he CKP uses a signal from the CMP sensor to

determine the position within the cycle. On I6 engines

the missing tooth is 60

° BTDC, while on V8 engines it

is 90

° BTDC.

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303-14-21

Powertrain Control Management

303-14-21

DESCRIPTION AND OPERATION (Continued)

Failure Mode

Crankshaft Position Sensor

The PCM will not be able to determine the current

engine speed or crankshaft position without the

correct signal from the CKP sensor. If the CKP sensor

fails, or an improper signal is received at the PCM,

fuel pump operation, spark and fuel injection are

suspended.

Testing

Sensor Test

1. Disconnect the harness from the CKP connector.
2. Measure the resistance across the connector

terminals using a suitable multimeter. Replace the

solenoid if not within specification.

CKP Resistance Specification

Item

Description

280 - 380

Ω

1

Sensor Housing

3. Check the harness for open circuits and short

2

Timing Cover

circuits.

3

Soft Iron Core

Temperature and Manifold Absolute

4

Coil Winding

Pressure Sensor

5

Toothed Wheel

The I6 Temperature And Manifold Absolute Pressure

6

Permanent Magnet

(T-MAP) sensor is located on the inlet manifold, below

The Coil On Plug (COP) Ignition System uses the

the throttle body. The 5.4, 3V V8 T-MAP sensor is

CKP and CMP signals to generate a digital Profile

located on the inlet manifold, adjacent to cylinder 8.

Ignition Pick-Up (PIP) signal. The PIP signal produces The 5.4L, 4V, V8 T-MAP sensor is located on the inlet

a rising edge when the crankshaft is at 10º BTDC of

manifold, adjacent to throttle body.

any cylinder s compression stroke. The PCM uses the

The T-MAP sensor is a combined pressure and

PIP signal to calculate spark timing.

temperature sensor that measures both intake air

Connections

temperature and manifold absolute pressure. The

Powertrain Control Module (PCM) uses these signals

PCM Pin A30. . . . . . . . . CKP Positive

for air mass calculations.

PCM Pin A41. . . . . . . . . CKP Negative

The T-MAP sensor uses a Piezo resistive sensor and

outputs a voltage proportional to the manifold

Circuit

absolute pressure. The voltage increases as manifold

vacuum falls.
A temperature-sensing element is incorporated into

the T-MAP senor to measure the temperature of the

intake air within the manifold. The temperature

element employs a thermistor that is sensitive to

temperature variations. The resistance of the

thermistor decreases as the temperature rises. The

sensor also measures barometric pressure when the

ignition is moving from the ON to the START positions

or whenever the throttle is wide open.

Connections

PCM Pin A38

. . . . . …. . . ...MAP Signal

PCM Pin A25

. . . . . …. . . ...IAT Signal

PCM Pin A36. .Vehicle Reference Voltage (VREF)

Diagnosis

PCM Pin A32. . . . . ..Signal Return (SIGRTN)

Diagnostic Trouble Codes (DTC) are retrieved through

the diagnostic connector using the WDS tester.

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