ECM/PCM/TCM - Intermittent Sensor Connection
90chevy34GMC NUMBER: 91-6E-36
GROUP: 6E Engine Emissions
DATE: December, 1990
CORPORATE
NUMBER: 066503R
SUBJECT: INTERMITTENT CONNECTION AT ECM/PCM/TCM SENSORS OR COMPONENTS
MODELS: 1991 LIGHT AND MEDIUM DUTY TRUCKS WITH ECM/PCM/TCM
Some 1991 Light and Medium duty trucks equipped with Electronic Control Modules (ECM) or Powertrain Control Modules (PCM) or Transmission Control Modules (TCM) may experience a condition in which the female terminals (150 series Metri-pack) in certain sensor or component connectors do not make a solid connection to the male
terminals in the opposing connectors. This can result in a intermittent connection. The 1991 Driveability & Emissions Manual (X-9136) directs a check of connections anytime an intermittent condition is found.
The following chart lists the component and circuit numbers that may experience this condition.
If an intermittent condition is found, the following test procedure should be performed. Insert a new mating male terminal, P/N 12047581 or 12045773, into the female terminal and check for a slight drag when the terminals are separated. Loose terminals without drag should be replaced.
Figure 1:
If the amount of drag is questionable, remove the terminal from the connector and inspect the terminal for the condition shown in FIGURE 1. Replace any terminals found defective with terminal P/N 12047680.
General directions of terminal replacement can be found on pages 3-146 thru 3-147 of the 1991 Driveability and Emissions Manual.
Important
Do not attempt to repair a defective terminal.
All of the above terminal part numbers are contained in J-38125 or are currently available from GMSPO.
WARRANTY INFORMATION For vehicles repaired under warranty use:
Labor Operation: T7096
Labor Time: This is a ST (Straight Time) operation which requires time documentation as detailed in the claims processing manual. Zone approval is required beyond .5 hours.
NOTE: Labor Operation is coded to base vehicle coverage in the warranty system.