Hombre XS Space Cab 2WD L4-2.2L CPC (1999)
The Powertrain Control Module (PCM) supplies either 5 or 12 volts to power various sensors or switches.
This is done through resistances in the PCM which are so high in value that a test light will not light when connected to the circuit. In some cases, even
an ordinary shop voltmeter will not give an accurate reading because its resistance is too low. Therefore, a 10 megohm input impedance digital voltmeter
is required to assure accurate voltage readings.
The Powertrain Control Module (PCM) controls most components with electronic switches which complete a ground circuit when turned ON. These
switches are arranged in groups of 4 and 7, called either a surface mounted quad driver module, which can independently control up to 4 outputs (PCM
terminals), or output driver modules, which can independently control up to 7 outputs. Not all outputs are always used.
Electrically Erasable Programmable Read Only Memory (EEPROM)
Electrically Erasable Programmable Read Only Memory (EEPROM)
The electrically erasable programmable read only memory (EEPROM) is a permanent memory chip that is physically soldered within the PCM.
The EEPROM contains the program and the calibration information that the PCM needs to Control powertrain operation.
Unlike the PROM used in past applications, the EEPROM is not replaceable. If the PCM is replaced, the new PCM will need to be programmed.
Equipment containing the correct program and calibration for the vehicle is required to program the PCM.
Reprogramming the PCM
PCM Re-Programming
The replacement PCM must be reprogrammed and the crankshaft position system variation procedure must be performed. Refer to the latest Techline
information on PCM re-programming for the Crankshaft Position system Variation Procedure.
1. Before beginning, ensure that the following conditions have been met:
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The battery is fully charged.
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The ignition is ON.
2. Program the PCM using the latest software matching the vehicle. Refer to the Techline terminal/equipment users instructions.
3. If the PCM fails to program, proceed as follows:
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Ensure that all PCM connections are OK.
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Inspect the Techline terminal/equipment for the latest software version.
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Attempt to program the PCM. If the PCM still cannot be programmed properly, replace the PCM. The replacement PCM must be
programmed.
4. Perform the PCM Password Learn procedure.
5. Perform the CKP System Variation Learn Procedure.
6. Perform the functional check as follows:
1. Clear the diagnostic trouble codes (DTCs).
2. Perform the On-Board Diagnostic System Check.
3. Start the engine and idle the engine for one minute.
4. Use the scan tool to inspect for DTCs.
