Tracker 4WD V6-2.5L VIN 4 (2001)
The PCM will turn OFF the MIL after 3 consecutive ignition cycles, in which the diagnostic runs, without the malfunction occurring. The DTC will
remain stored in the PCM memory after the MIL is OFF.
Fail-Safe Function
When a malfunction occurs within the engine control system, the PCM maintains control over the fuel injection system, the idle speed control system,
etc. The PCM controls these systems by using calculated values and backup programs stored within the PCM.
This function is called the fail-safe function. With the fail-safe function, a certain level of engine performance is available even when a malfunction
occurs. The fail-safe function prevents a complete loss of engine performance.
The systems covered by the fail-safe function are as follows:
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The Engine Coolant Temperature (ECT) sensor
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The Throttle Position (TP) sensor
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The Mass Air Flow (MAF) sensor
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The Intake Air Temperature (IAT) sensor
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The Vehicle Speed Sensor (VSS)
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The Barometric (BARO) pressure sensor
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The fuel level sensor
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The Central Processing Unit (CPU) in the PCM
Control Module Learning Ability
The control module has a "learning" ability which enables the control module to make corrections for minor variations in the fuel system. This learning
ability can improve driveability. Disconnecting the battery resets the learning process. A change in the vehicle's performance may be noticed when a
reset occurs. The vehicle operator can teach the control module in order to regain some of the lost vehicle performance.
In order to teach the control module, ensure that the engine is at operating temperature and drive the vehicle at part throttle with moderate acceleration.
The vehicle may also be operated at idle conditions until normal performance returns.
PCM Output Controls
IMPORTANT: Do not use the scan tool's Output Control feature until the vehicle is at normal operating temperatures. The PCM will not respond to a
scan tool request for Output Controls until the engine coolant temperature is above 80°C (175°F). Failure to wait for normal operating temperatures can
result in the incorrect diagnosis of a driveability problem.
Output Controls are disabled when any DTCs are stored by the PCM. Clear all DTCs before using Output Controls on the scan tool.
The Powertrain Control Module (PCM) can be directed by the Tech 2 scan tool to operate certain solenoids, valves, motors, and switches. This scan tool
function is generally referred to as Output Controls. Output controls can be found under Special Functions on the Tech 2 scan tool. Operating a PCM
controlled device with the scan tool should be limited to a maximum of ten seconds per test period.
Reading Diagnostic Trouble Codes Using A Scan Tool
The procedure for reading diagnostic trouble codes is to use a diagnostic scan tool. Follow the instructions supplied by the scan tool manufacturer in
order to read DTCs accurately.
Clearing Diagnostic Trouble Codes
IMPORTANT: Do not clear the DTCs unless directed to do so by the service information provided for each diagnostic procedure. The Freeze Frame
data which may help diagnose an intermittent fault will be erased from the memory when the DTCs are cleared.
The PCM will begin to count the warm-up cycles when the fault that caused the DTC to be stored into memory has been corrected. The DTC will
automatically be cleared from the PCM memory when the PCM has counted forty (40) consecutive warm-up cycles with no further faults detected.
Diagnostic Trouble Codes (DTCs) can be cleared using a scan tool. In order to clear DTCs, use the scan tool's clear the DTCs or clear the information
function. Follow the instructions supplied by the scan tool manufacturer.
Data Link Connector (DLC)