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HOMESERVICE MANUALSSATURN1993SC L4-1.9L SOHC VIN 9REPAIR AND DIAGNOSISPOWERTRAIN MANAGEMENTCOMPUTERS AND CONTROL SYSTEMSTECHNICAL SERVICE BULLETINSCUSTOMER INTERESTENGINE CONTROLS - PCM CANNOT COMMUNICATE WITH PDT
1993 Saturn SC L4-1.9L SOHC VIN 9
Engine Controls - PCM Cannot Communicate With PDT
1993 Saturn SC L4-1.9L SOHC VIN 9SECTION Engine Controls - PCM Cannot Communicate With PDT
NO.: 92-T-47B
DATE: April, 1995
GROUP: Engine
CORPORATION NO.: 286002R
SUBJECT:
PCM Cannot Communicate with PDT or Saturn Service Stall System (Cycle Ignition On/Off)
Due to revisions in the affected model years with the addition of 1995 Saturns, this bulletin supercedes bulletin 92-T-47A, which should be discarded.
MODELS AFFECTED:
1991 - 1995 Saturn's
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.
IMPORTANT:
If engine coolant temperature is 42°C (106°F) 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 appropriate "Electronic Engine Controls Service Manual."
DISCLAIMER
DATE: April, 1995
GROUP: Engine
CORPORATION NO.: 286002R
SUBJECT:
PCM Cannot Communicate with PDT or Saturn Service Stall System (Cycle Ignition On/Off)
Due to revisions in the affected model years with the addition of 1995 Saturns, this bulletin supercedes bulletin 92-T-47A, which should be discarded.
MODELS AFFECTED:
1991 - 1995 Saturn's
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.
IMPORTANT:
If engine coolant temperature is 42°C (106°F) 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 appropriate "Electronic Engine Controls Service Manual."
DISCLAIMER
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.