Engine Controls - ECM Wiring Harness Repair: Overview

91mitsubishi03

NO. TSB-91-13-003

DATE February, 1991

MODEL 1990-91 PRECIS


SUBJECT:

REPAIR OF E.C.U. WIRING HARNESS


PURPOSE

This service bulletin describes a repair to the Electronic Control Unit (ECU) wiring harness on 1990-91 Precis vehicles.

DESCRIPTION

If you should encounter a 1990-91 Precis with one or more of the following symptoms, there may be a high resistance in the Throttle Position Sensor (TPS) ground circuit.
- "Check Engine" light comes on.
- Fault code "15" in ECU.
- Engine dies while idling.
- A/C compressor won't turn on.

The cause of these symptoms may be a faulty crimp connection in the wiring harness to the TPS. To repair the wiring harness, locate and solder the crimp connection.

There are two different wiring harnesses which may be found on the vehicle; one made by Kyung Shin, and the other made by Tong Hae (Dong Hae). The remainder of this service bulletin describes proper soldering technique, determining which harness is present on the vehicle, and repair steps for both Kyung Shin and Tong Hae (Dong Hae) harnesses.

PROCEDURE

WARNING: Always wear eye protection while soldering.

Since soldering of the crimp connection is the most important step in this repair procedure, pay strict attention to the following instructions.

Materials:

- Soldering gun or high output pencil-type soldering iron
- Solder (thin, rosin-core lead)
- Block of wood