Control Unit (ECU)

NOTE: YUGO RECALL #91V130 WATER INFILTRATION AT (ECU)

On 1990 and 1991 E.F.I. GV Plus cars there is the possibility of water infiltration at the three studs that support the E.C.U. Check your vehicle for the presence of a colored sticker on the trim panel below the passengers side dashboard, indicating recall has been performed.

Fig. 3 Bosch Motronic Electronic Engine Control System Terminal Identification:

Perform the following test procedure using a suitable digital volt/ohmmeter, referring to Fig 3 for terminal identification.
1. Locate ECU behind passenger side of instrument panel, then disconnect 35 pin connector from ECU.
2. With ignition switch in Run position, probe ECU terminal 35 with voltmeter positive lead and ECU terminal 5 with negative lead. If battery voltage is not present, turn ignition switch Off and proceed as follows:
a. Inspect fuse near main relay.
b. Check resistance between ECU terminal 5 and battery negative terminal, resistance should be approximately 0 ohms but no greater than 1 ohm. If infinite resistance is indicated check for an open. If high resistance is indicated, check continuity between ECU terminal 35 and main relay terminal 87.
c. With ignition switch in Run position, check for battery voltage at main relay terminals 85 and 86. If battery voltage is not present, check for continuity between main relay terminal 85 and ground, and between terminal 85 and ignition switch terminal 15.
d. Check for battery voltage on main relay connector terminals 30 and 85. If readings are identical, check for damage to wires between main relay connector terminal 85 and ground, and between main relay connector terminal 30 and the battery.
e. If all wires and connections test good, and no voltage is present at ECU, replace main relay.