The 1988 - 1989 TBI SMEC

Description

This page contains information specific to the 1990 through 1993 TBI (throttle body injected, non-turbo) Single Board Engine Controller (SBEC). If you are not familiar with what the SBEC is, please see the Understanding The Chrysler Engine Control Unit page before reading this one.

Like the SMEC, the SBEC 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 address latched 32kx8 EPROM (87C257).

Functionally, the 1990 through 1993 TBI SMECs are nearly the same and are therefore interchangeable. Internally however they did evolve over the years, particularly in the software.

Connectors

The SBEC has a single, bolt-on 60-way connector. The following section contains a diagram and pin-out for it. 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	K01	20	DG/RD*	MAP sensor signal
2	K02	20	TN/BK*	Coolant temperature sensor signal
3	A14	16	RD/WT*	Automatic shutdown (ASD) relay power feed sense
4	K04	18	BK/LB*	Signal ground to sensors
5	Z11	16	BK	Signal ground source from top rear of engine
6	K06	18	VT	5V power supply to MAP sensor and TPS
7	K07	18	OR	8V power supply to ignition reference sensor
8	-	-	-	Not used
9	A21	14	DB	Ignition "start"/"run" power feed
10	-	-	-	Not used
11	Z12	16	BK/TN*	Power ground source from top rear of engine
12	Z12	16	BK/TN*	Power ground source from top rear of engine
13	-	-	-	Not used
14	-	-	-	Not used
15	-	-	-	Not used
16	K11	18	WT/DB*	Fuel injector driver output
17	-	-	-	Not used
18	-	-	-	Not used
19	K19	18	BK/GY*	Ignition coil driver output
20	K20	18	DG	Alternator field coil driver output
21	-	-	-	Not used
22	K22	18	OR/DB*	Throttle position sensor (TPS) signal
23	-	-	-	Not used
24	K24	18	GY/BK*	Ignition reference sensor signal
25	D21	20	PK	Serial communications interface (TX)
26	D01	20	VT/BR*	Serial bus B+
27	C20	18	BR	A/C damped pressure switch signal
28	-	-	-	Not used
29	K29	18	WT/PK*	Brake pedal switch signal
30	T24	20	BR/LB*	Neutral safety switch signal
31	C27	20	DB/PK*	Radiator fan relay output
32	G03	20	BK/PK*	Check engine lamp output
33	V36	20	TN/RD*	Speed control servo output (vacuum)
34	C13	20	DB/OR*	A/C cutout (WOT) relay output
35	K35	20	GY/YL*	Exhaust gas return (EGR) solenoid output (California only)
36	-	-	-	Not used
37	-	-	-	Not used
38	-	-	-	Not used
39	K39	18	GY/RD*	AIS motor output (winding 2)
40	K40	18	BR/WT*	AIS motor output (winding 1)
41	K41	18	BK/DG*	Heated oxygen sensor signal
42	-	-	-	Not used
43	G21	20	GY/LB*	Tachometer signal to instrument cluster
44	-	-	-	Not used
45	D20	20	LG	Serial communications interface (RX)
46	D02	20	WT/BK*	Serial bus B+
47	G07	20	WT/OR*	Speed/Distance sensor signal
48	V31	20	BR/RD*	Speed control switch set signal
49	V32	20	YL/RD*	Speed control switch on/off signal
50	V33	20	WT/LG*	Speed control switch resume signal
51	K51	20	DB/YL*	ASD relay output
52	K52	20	PK/BK*	Purge canister solenoid output
53	V35	20	LG/RD*	Speed control servo output (vent)
54	K54	20	LG/WT*	Power transfer unit (PTU) unlock output
55	-	-	-	Not used
56	-	-	-	Not used
57	-	-	-	Not used
58	-	-	-	Not used
59	K59	18	VT/BK*	AIS motor output (winding 1)
60	K60	18	YL/BK*	AIS motor output (winding 2)

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Updated 12/08/2004.