Explorer 2WD V6-245 4.0L SOHC VIN E EFI (1997)
Multifunction Electronic Control Module: Description and Operation
Without Power Windows and/or Power Door Locks
CTM Controlled Functions
The Central Timing Modules (CTMs) are equipped only on the two wheel drive vehicles without power windows and/or power locks. All other vehicles
have a Generic Electronic Module (GEM).
NOTE: CTM diagnostics are not compatible with the New Generation STAR (NGS) tester (i.e., module cannot communicate over the ISO 9141
diagnostic link with the NGS tester); instead the diagnostics are internal to the module. The diagnostic mode is entered by shorting two pins of a
diagnostic connector together. The diagnostic operations are described in each subsection.
The Central Timing Module (CTM) incorporates the functions of several different modules into one and offers diagnostics to easily locate and repair
concerns affecting the subsystems that it controls.
The CTM constantly monitors the systems under its control and reports a concern in the form of Diagnostic Trouble Code (DTC). A DTC can be
retrieved by performing an On-Demand self test. When the diagnostic mode is activated, the CTM will output trouble codes, if any, to the technician by
flashing the door ajar lamp and simultaneously sounding the chime in a certain order. These codes may then be used to help diagnose potential
intermittent failures.
NOTE: The CTM can only detect open circuit/short to ground faults when it is not energizing a load, and short to battery faults when the CTM is
attempting to energize a load.
The CTM controls the following systems:
^
Wiper/Washer.
^
Warning Chimes and Lamps.
^
Battery Saver.
^
Interior Lighting.
NOTE: The CTM has a sleep function to minimize battery consumption. During the sleep mode, the CTM turns OFF all outputs and monitors only the
following:
^
Door Ajar (driver door, passenger door, lift gate, left rear, and right rear doors).
^
Key is inserted or removed.
^
The ignition switch is turned from OFF to RUN.
^
The ignition switch is turned from OFF to ACC.
^
Driver door handle switch is activated.
If a change in status occurs at one of these inputs while the CTM is asleep, the CTM will "wake up." When the CTM awakens, it performs an internal
self-test and begins normal operation. At this point, the CTM will have all of its functions operational.
The CTM will go into the sleep mode immediately after both of the following conditions have been met:
^
Key in OFF or key not in ignition.
^
After 40 minutes with no change on any wake-up input.
The CTM control system has two modes of operation, the normal operating mode and tester dependent diagnostics mode.
The normal operation of the CTM can detect errors. An integral part of the normal CTM operation is the continuous diagnostics capabilities. Continuous
diagnostics detects errors and changes the CTM control strategy. There is no warning light for the CTM; therefore, a DTC will direct you to the CTM.
Examples of faults that may be detected during normal operation include:
^
CTM continuous self-test (RAM, ROM, EEPROM, A/D checking).
^
Illogical combinations of input signals.
^
Output driver monitoring (open circuit/short to GND, short to battery).
Windshield Wiper/Washer Control
There are four modes of operation for the wipers: interval, slow, fast, and wash. These modes are only active with the ignition in the RUN or ACC
position.
MIST
When the wash button is pressed for less than .3 second, with the multi-function switch in the OFF position, the wiper motor will perform a
single wipe without a wash. If the wash button is held longer than .3 seconds, up to 10 seconds, the washer pump runs together with low speed
wipes while the switch is held followed by two to three wipes after the switch is released.
INTERVAL
For interval, the time delay between low-speed wipes will range from 1.5 to 20 seconds. If the wash switch is pressed for 0.3 to 10 seconds in
this mode the washer pump will energize until the wash switch is released but the wiper will continue for two to three wipes then return to the
