EEC IV Code Reader
For 2.9L 12 Valve & Early Tdi
Ready Made units are available
Introduction
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readers, but this relates to the earlier engine Management Systems and is
obsolete.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 Ford’s 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 Scorpio’s 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
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Scorpio 95+ Datalink OBD2 Pinouts |
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PIN |
Standard |
Scorpio |
Alex(24V,16v) |
2.9 12v |
TDi |
Comments |
| 1 |
Discretionary* (GMLAN SW CAN Line) SW CAN 1 |
Ignition Timing |
|
X |
X |
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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 |
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X |
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Non EEC-V |
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4 |
Chassis Ground AUX L 23 |
Chassis Ground |
X |
X |
X |
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5 |
Signal Ground PWR GND 13 |
Signal Ground |
X |
X |
X |
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| 6 |
Discretionary* (GMLAN HS CAN H) HS CAN H 14 |
N/A |
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| 7 |
Line of ISO 9141-2 ISO K 8 |
K-Line ISO9141 |
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X |
X |
Main Connection ISO9141 |
| 8 |
Discretionary* J1708H 19 |
N/A |
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| 9 |
Discretionary* (GM ALDL) AUX H 24 |
Battery Power |
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X |
X |
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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 |
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X |
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Non EEC-V |
| 12 |
Discretionary* LSFT H 3 |
N/A |
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| 13 |
Discretionary* LSFT L 4 |
Module Programming Signal |
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X |
X |
Ford Proprietary..wds ?? |
| 14 |
Discretionary* (GMLAN HS CAN L) HS CAN L 15 |
N/A |
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| 15 |
L line of ISO 9141-2 ISO L 7 |
N/A |
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| 16 |
Un-switched Vehicle Battery
Positive VBATT 25 |
Battery Power |
X |
X |
X |
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PIN 7 ISO9141 BUS USED FOR MULTIPLEX NOT PCM |
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The Scorpio’s 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)
 | Engine must be at normal operating temperature. |
| Switch off AC |
| Switch off Engine |
| Engage transmission to Park or Neutral if manual gearbox |
| Insert reader with switch OFF |
| Turn on ignition |
| Switch on reader |
| Wait for 1 pulse |
| Depress fully and release throttle |
| Reader will send Fast Codes |
| Reader will then pulse the KOEO result code (and repeat it). 11 is No Fault. |
| Wait for a single pulse; this signifies the end of the KOEO test. |
| Reader will now pulse out (twice) any stored memory fault code or 11 if
none. |
| Switch off ignition |
| Switch off reader |
