DESCRIPTION & OPERATION
The electric cooling fan system may consists of a single speed or 2-speed cooling fan or fans controlled by Powertrain Control Module (PCM), on all models, and through the Constant Control Relay Module (CCRM) on Escort and Mustang. On all models, a low speed fan control relay and/or a high speed fan control relay is used. The electric cooling fan or fans are activated when ignition switch is in ON position and engine coolant exceeds a specified temperature. On vehicles equipped with A/C, cooling fan is also active when A/C is on.
Note. Unless specified otherwise, references to Escort include Escort Coupe (ZX2).Villager is not covered in this article. See ELECTRIC COOLING FANS - EEC - VILLAGER article.
Note. This article only tests the Fan Control (FC) relay and Constant Relay Control Module (CCRM) circuits. Other test may be referenced while performing electric cooling fan diagnosis. For complete Ford EEC-V system diagnosis, see SELF-DIAGNOSTICS - EEC-V - GASOLINE article in ENGINE PERFORMANCE.
Description
KOEO on-demand self-test is a functional test of PCM performed with ignition key on, engine off. This test checks if PCM inputs and outputs are functioning electronically without any faults. A fault must be present at time of testing for KOEO on-demand self-test to detect a fault.
KOER on-demand self-test is a functional test of PCM performed with ignition key on, engine running. A check of certain inputs and outputs is made during operating conditions and normal operating temperature. The brake pedal position, transmission control and power steering switch tests are part of KOER on-demand self-test and must be performed during this operation (if applicable). A fault must be present at time of testing for KOER on-demand self-test to detect a fault.
Continuous memory self-test is a functional test of PCM performed under any condition (engine running or engine off) with ignition on. Unlike KOEO and KOER self-tests which can only be activated on demand, continuous monitor is always active in monitoring the system. When a fault is detected, DTC will be stored in memory. This makes it possible to diagnose intermittent faults.
There are 2 types of Continuous Memory DTCs. Emission related DTCs will turn on the Malfunction Indicator Light (MIL) on instrument cluster. Non-emission DTCs will not turn on MIL. On emission related MIL codes, PCM will store DTC in continuous memory at first detection of problem. The MIL will not be illuminated and DTC is reported as a pending DTC. If same problem is detected in next drive cycle, MIL will be illuminated. MIL will go out if 3 consecutive drive cycles have been run. An emission related pending DTC or non-emission DTC will be erased after 40-80 warm-up cycles or PCM reset.
PID mode allows access to certain data values, analog and digital inputs and outputs, calculated values, and system status information. There are 2 types of PID lists available. The first is Generic OBD-II PID list. This is a standard set of PIDs that all scan tools can access. The second is a Ford specific PID list that can be accessed by using New Generation Star (NGS) scan tool. When accessing any PIDs from the specific PID list, the values are continuously updated.
HARDWARE LIMITED OPERATIONAL STRATEGY (HLOS)
If a number of system or sensor failures are present and PCM is not receiving enough information to operate, PCM will switch to HLOS mode. PCM will output fixed values to allow operation of vehicle. Driveability concerns will be present. PCM will not output diagnostic trouble codes in this mode.
OBD-II Drive Cycle Description
OBD-II drive cycle is a pattern of driving in which the PCM will execute all OBD-II diagnostic monitors. Drive cycle can be used to cause a DTC to set if a fault is present or to verify that a DTC will not return after a repair has been completed. If drive cycle is complete and DTC P1000 is not cleared, repeat entire drive cycle.
Note. Rough road conditions may prevent certain steady state conditions and steady accelerations from validating the transmission and load related monitors.
Flash Electronically Erasable Programmable Read Only Memory (EEPROM) is contained in an Integrated Circuit (IC) inside of Powertrain Control Module (PCM). The EEPROM contains the vehicle strategy and any calibration information specific to vehicle. The IC is reprogrammable and at times it may become necessary to reprogram or reflash the entire contents. This is usually due to an after production strategy change or the Vehicle Identification (VID) area has been previously reprogrammed and has reached its limit. The VID block can be tailored to accommodate various hardware changes made since vehicle production. This procedure can only be performed using Ford's Service Bay Technical System (SBTS) or equivalent.
A replacement PCM will have a label stating PROGRAMMING REQUIRED. This indicates that it is necessary to retrieve VID data from the original PCM before removing PCM from vehicle. This procedure can be performed using New Generation Star (007-00500) scan tool or equivalent. See FLASH VEHICLE IDENTIFICATION (VID) BLOCK PROCEDURE . If original PCM is nonfunctional, it will be necessary to manually reprogram VID block. This procedure can only be performed using Ford's Service Bay Technical System (SBTS) or equivalent.
FLASH VEHICLE IDENTIFICATION (VID) BLOCK PROCEDURE
Note. If using a generic scan tool, follow scan tool manufacturer's instructions to perform FLASH VEHICLE IDENTIFICATION (VID) BLOCK PROCEDURE.
- To perform this procedure NGS scan tool, Ford Service Function (FSF) card and NGS Flash Cable (007-00531) must be used. Plug flash cable into scan tool. Plug other end of flash cable into Data Link Connector (DLC). From the scan tool main menu, select SERVICE BAY FUNCTIONS, PCM-POWERTRAIN CONTROL MODULE and then PROGRAMMABLE MODULE INSTALLATION.
- Scan tool display should show 2 selections. The first is selection is for old PCM information to be retrieved and stored. The second selection is for restoring new PCM with information that has been retrieved from the old PCM. Follow scan tool display instructions or refer to instruction sheet included with FSF card. If Vehicle Identification (VID) block has been reprogrammed previously, scan tool will display a message indicating the need to reflash entire Integrated Circuit (IC). This procedure can only be performed using Ford's Worldwide Diagnostic System (WDS).