EXPERTEC TSB (92-T-47B)

Publication date: 1995-04-01
Reference number: 92-T-47B

EXPERTEC TSB

TECHNICAL SERVICE BULLETIN

Reference Number(s): 92-T-47B, Date of Issue: 04/01/95

PCM CANNOT COMMUNICATE WITH - PDT OR SSS (CYCLE IGN. ON/OFF)

Model(s): 1991 AND 1995 SATURNS

Bulletin No.: SATURN 92-T-47B

Date: 04/01/1995

CONDITION

A serial communication interface (SCI) failure causing no powertrain control module (PCM) communication with portable diagnostic tool (PDT) and Service Stall System (SSS). With a SCI failure, the PDT or SSS cannot establish communication with the PCM, however, the vehicle's operation is normal.

CAUSE

In order for the PDT to communicate with the PCM, the PCM must issue a polling message. During certain communication modes, the PCM does not receive all of the information required to issue the poll message and will continue to wait for further data, causing a communication problem.

CORRECTION

Turn the ignition off, wait 10 seconds to reset the PCM and then start the vehicle.

NOTE: If engine coolant temperature is 42 degrees Celsius (106 degrees Fahrenheit) or above, it may take up to five minutes of ignition off time to reset the PCM. If the PCM will not communicate after the ignition is cycled, refer to the "Diagnostic IV" chart in the "Electronic Engine Controls Service Manual."