The 1988 - 1989 TBI SMEC

[ 60 Way Connector | 14 Way Connector ]

Description

This page contains information specific to the 1988 and 1989 TBI (throttle body injected, non-turbo) Single Module Engine Controller (SMEC).  If you are not familiar with what the SMEC is, please see the Understanding The Chrysler Engine Control Unit page before reading this one.

The SMEC uses a Motorola 6811 processor, which has twice the processing power of the 6803 that was used in the logic modules, reducing the loop time to 11 milliseconds.  The software and calibration tables are stored in a single 16kx8 EEPROM (27C128).

Functionally, the 1988 and 1989 TBI SMECs are the same and are therefore interchangeable.  Internally however they do differ, particularly in the software.  The 1988 SMECs are based largely on the 1987 logic module code, while the 1989 SMECs appear to have a great deal of new code. This provided some additional functionality, such as greater on board diagnostic capability, returning from limp-in mode while driving if a sensor starts working again, etc).


Connectors

The SMEC has two connectors: one bolt-on 60-way connector, which leads to the logic board and one 14-way large pin connector, which leads to the power board.  The following sections contain a diagram and pin-out for each.  The wire colors are in the color/tracer* format (BK/WT* = black wire with a white tracer).  Below is a list of color abbreviations:


Code Color Code Color Code Color
BK Black LB Light Blue TN Tan
BR Brown LG Light Green VT Violet
DB Dark Blue OR Orange WT White
DG Dark Green PK Pink YL Yellow
GY Grey RD Red * tracer

60 Way Connector

Pin Circuit Wire Gauge Wire Color Function
1 K4 20 DG/RD* MAP sensor signal
2 - - - Not used
3 K10 20 TN/WT* Coolant temperature sensor signal
4 N5 18 BK/LB* Signal ground to sensors
5 K5 16 BK/WT* Signal ground source from top rear of engine
6 - - - Not used
7 X33 20 WT/LG* Speed control switch resume signal
8 X32 20 YL/RD* Speed control switch on/off signal
9 X31 20 BR/RD* Speed control switch set signal
10 B1 18 WT Ignition "run" power feed
11 - - - Not used
12 K14 18 DB/WT* Ignition "start"/"run" power feed from power board (J2)
13 K8 20 VT/WT* 5V power supply to MAP sensor and TPS
14 R31 20 DG/OR* Voltage regulation signal to power board
15 K9 18 LB/RD* Power ground source from top rear of engine
16 K9 18 LB/RD* Power ground source from top rear of engine
17 N2 18 BR/WT* AIS motor output (winding 1)
18 N4 18 YL/BK* AIS motor output (winding 2)
19 N1 18 GY/RD* AIS motor output (winding 2)
20 N3 18 VT/BK* AIS motor output (winding 1)
21 K13 18 BK/RD* Throttle body temperature sensor signal
22 K7 18 OR/DB* Throttle position sensor (TPS) signal
23 N11 18 BK/DG* Heated oxygen sensor signal
24 - - - Not used
25 - - - Not used
26 - - - Not used
27 - - - Not used
28 - - - Not used
29 D40 18 WT/PK* Brake pedal switch signal
30 S4 20 BR/YL* Neutral safety switch signal
31 DK20 20 LG Serial communications interface (RX)
32 - - - Not used
33 K16 20 VT/YL* Fuel injector control signal to power board
34 K15 20 YL Anti dwell control signal to power board
35 - - - Not used
36 Z6 20 LB/BK* Fuel monitor signal to electronic navigator
37 - - - Not used
38 - - - Not used
39 - - - Not used
40 S6 20 GY/YL* Exhaust gas return (EGR) solenoid output (California only)
41 J1 16 RD Direct battery feed
42 - - - Not used
43 - - - Not used
44 - - - Not used
45 C20 18 BR A/C damped pressure switch signal
46 - - - Not used
47 N7 18 GY/BK* Ignition reference sensor signal
48 G7 20 WT/OR* Speed/Distance sensor signal
49 - - - Not used
50 T21 20 GY/LB* Tachometer signal to instrument cluster
51 DK21 20 PK Serial communications interface (TX)
52 N6 18 OR 8V power feed from power board
53 X36 20 TN/RD* Speed control servo output (vacuum)
54 K1 20 PK/WT* Purge canister solenoid output
55 U3 20 OR/BK* Shift indicator light output
56 N13 20 DB/OR* A/C cutout (WOT) relay output
57 C27 20 DB/PK* Radiator fan relay output
58 K19 20 DB/YL* ASD relay output
59 K3 20 BK/PK* Check engine lamp output
60 X35 20 LG/RD* Speed control servo output (vent)

14 Way Connector

Pin Circuit Wire Gauge Wire Color Function
1 N6 18 OR 8V power supply to logic board
2 K5 16 BK/WT* Signal ground source from top rear of engine
3 K14 18 DB/WT* Ignition "start"/"run" power feed to logic board and ASD relay (J2)
4 J2 14 DB Ignition "start"/"run" power feed
5 - - - Not used
6 J9 16 BK Power ground source from top rear of engine
7 J9 16 BK Power ground source from top rear of engine
8 K16 20 VT/YL* Fuel injector control signal from logic board
9 Y11 18 WT Fuel injector driver output
10 - - - Not used
11 R31 20 DG/OR* Voltage regulation signal from logic board
12 J5 18 BK/YL* Ignition coil driver output
13 K15 20 YL Anti dwell control signal from logic board
14 R3 18 DG Alternator field coil driver output

Return to the Engine Control Unit page

Updated 12/08/2004.

Copyright © 1996-2004 Russ W. Knize.