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  EEC-IV Code Reader

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EEC IV Code Reader
For 2.9L 12 Valve & Early Tdi

Ready Made units are available

The Ford Scorpio 95+ was available with several engine variants, and different Powertrain Control Modules (PCM).  PCM is a term that refers to OBDII-compliant systems, of which the EECV is one. The terminology Electronic Control Unit (ECU), or Engine Management System (EMS) may be more familiar to some readers, but this relates to the earlier engine Management Systems and is obsolete. In this discussion and in keeping with Fordís own descriptions, the term PCM will be used.

Most variants within the range use the EECV PCM and OBDII diagnosis can be used. However the 2.9L 12 Valve and early 2.5L Turbo Diesel use the EEC IV, and these are not compatible with OBDII readers.

The 2.9L 12 Valve and also possibly the very early 2.5 TDi utilise the EEC IV PCM, this does allow for diagnostics via the Star Code system, sometimes referred to as On Board Diagnostics 1 (OBD1). Although this system is not as versatile as OBD2, it does allow the reporting of fault codes from the PCM, these fault codes refer to various sensors and variables concerned with the engine.

Communicating with Scorpioís EEC IV
The EEC IV uses a very simple interface for diagnostics. Two Signals are used, Self Test Input (STI) and Self Test Output (STO). The Self Test Input is connected to Ground (0V) to initiate the tests. The Self Test Output is a 5V output, that can drive, for example an LED or voltmeter.
These connections are available on the Data Link Connector (DLC); this is located in the change cubby to the right (right hand drive) of the steering wheel. The following picture shows its location, the plastic cover must be unclipped to reveal the connector.

The DLC connector contains various signals, depending on the PCM, these are shown in the following table, however for the EEC IV reader we are interested in pins 3, 5, 11 & 16, these being, STO, Signal Ground, STI & +12V Battery Power.

Scorpio 95+ Datalink OBD2 Pinouts

  Scorpio 95+ Datalink OBD2 Pinouts        


PIN Standard Scorpio Alex(24V,16v) 2.9 12v TDi Comments
1 Discretionary* (GMLAN SW CAN Line) SW CAN 1 Ignition Timing   X X  
2 + line of SAE J1850 J1850 VPW 2 SPC+ X X X J8150+
3 Discretionary* (GMLAN MS CAN H) MS CAN H 16 Start Test Output   X   Non EEC-V
4 Chassis Ground AUX L 23 Chassis Ground X X X  
5 Signal Ground PWR GND 13 Signal Ground X X X  
6 Discretionary* (GMLAN HS CAN H) HS CAN H 14 N/A        
7 Line of ISO 9141-2 ISO K 8 K-Line ISO9141   X X Main Connection ISO9141
8 Discretionary* J1708H 19 N/A        
9 Discretionary* (GM ALDL) AUX H 24 Battery Power   X X  
10 - line of SAE J1850 J1850 PWM L 5 SPC- X X X J8150 -
11 Discretionary* (GMLAN MS CAN L) MS CAN L 17 Start Test Input   X   Non EEC-V
12 Discretionary* LSFT H 3 N/A        
13 Discretionary* LSFT L 4 Module Programming Signal   X X Ford Proprietary..wds ??
14 Discretionary* (GMLAN HS CAN L) HS CAN L 15 N/A        
15 L line of ISO 9141-2 ISO L 7 N/A        
16 Un-switched Vehicle Battery Positive VBATT 25 Battery Power X X X  















The Scorpioís DLC, is in fact the same physical connector as defined by the OBD2 standard, if manufacturing your own tester a blank male OBD2 connector is required. These are available if required.

The following diagram shows the connections for the reader.

Using the Reader

KOEO Test (Key on Engine Off)

bulletEngine must be at normal operating temperature.
bulletSwitch off AC
bulletSwitch off Engine
bulletEngage transmission to Park or Neutral if manual gearbox
bulletInsert reader with switch OFF
bulletTurn on ignition
bulletSwitch on reader
bulletWait for 1 pulse
bulletDepress fully and release throttle
bulletReader will send Fast Codes
bulletReader will then pulse the KOEO result code (and repeat it). 11 is No Fault.
bulletWait for a single pulse; this signifies the end of the KOEO test.
bulletReader will now pulse out (twice) any stored memory fault code or 11 if none.
bulletSwitch off ignition
bulletSwitch off reader

To clear any stored codes switch off the reader BEFORE switching off
the ignition.

KOER Test (Key on Engine Run)

bulletEngine must be at normal operating temperature.
bulletSwitch off AC
bulletInsert reader with switch OFF
bulletStart engine
bulletSwitch on reader
bulletReader will pulse out half the number of cylinders (i.e. 3 for the V6)
bulletThe revs will rise and fall as tests are run.
bulletWait for a single pulse
bulletDepress fully and release throttle
bulletReader will flash the Fast Codes
bulletReader will then pulse the KOER test result code (twice).


A web search for EEC IV, will return many interesting links, a few are listed here: note - these are external links.




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