AUTOMATIC TRANSMISSION (AW30-40LE) 7A–23
INTERMITTENT CONDITIONS
If the Tech2 displays a code as intermittent, or if after a
test drive a code does not reappear, the problem is most
likely a faulty electrical connection or loose wiring.
Terminals should always be the prime suspect.
Intermittent rarely occur in sophisticated electronic
components such as the Transmission Control Module
(TCM).
When an intermittent problem is encountered, check
suspect circuits for:
• Poor terminal to wire connection.
• Terminals not fully seated in the connector body
(backed out).
• Improperly formed or damaged terminals.
• Loose, dirty, or corroded ground connections.
HINT: Any time you have an intermittent in more than
one circuit, check whether the circuits share a
common ground connection.
• Pinched or damaged wires.
• Electro-Magnetic Interference (EMI)
HINT: Check that all wires are properly routed away
from spark plug wires, distributor wires, coil,
and generator. Also check for improperly
installed electrical options, such as lights, 2-
way radios, etc.
Use the F2: SNAPSHOT mode of the Tech2 to help
isolate the cause of an intermittent fault. The snapshot
mode will record information before and after the
problem occurs. Set the snapshot to "trigger" on the
suspect code (or codes) or, if you notice the repor ted
symptom during test drive, trigger the snapshot
manually.
After the snapshot has been triggered, command the
Tech2 to play back the flow of data recorded from each
of the various sensors. Signs of an intermittent fault in a
sensor circuit are a sudden unexplainable jump in data
values out of the normal range.
