Engine Controls - Intermittent Connection to the ECM

88chevy13

GMC NUMBER: 88-T-133

GROUP: 6E - Engine Emissions

DATE: July, 1988


CORPORATE
NUMBER: 838109
SUBJECT: INTERMITTENT CONNECTION TO THE ECM

MODELS: 1988 ALL TRUCKS EQUIPPED WITH ECMS

FIGURE 1:

Some 1988 Trucks equipped with ECMs may experience a condition in which the female terminals in the connector to the ECM do not make a solid connection to the male pins in the ECM (see illustration). This can result in an intermittent condition, in any circuit operated by the ECM. The Driveability and Emissions Manual directs a check of connections any time an intermittent condition is found. Example: "Service Engine Soon" light on but no trouble codes are stored in the ECM. This may be the cause of some of these conditions.
If this condition exists, visually inspect the terminal using a flashlight, or use a .95 mm pin gage. The gage should not pass freely through the female terminal. Do not probe the terminal with anything other than the pin gage, as probing could damage the terminal. If the female terminal does not grip properly, replace the terminal with P/N 12020757. General directions on wiring repair are shown on page 3-92 thru 3-94 of the 1988 Driveability and Emissions Manual X-8836.
For vehicles repaired under warranty use:
Labor Operation: N6278
Labor Time: .5 hr