7A2-16 DIAGNOSIS (JR405E)
INTERMITTENT DIAGNOSIS
If the Tech 2 displays any codes as intermittent, or if after a test drive any codes 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 TCM.
When an intermittent problem is encountered, check suspect circuits for:
Poor terminal to wire connection.
Terminals not fully seated in the connector body.
Improperly formed or damaged terminals.
Loose, dirty or damaged terminals.
Any time you have an intermittent in more than one circuit, check whether the circuits share a common ground
connection.
Pinched or damaged wires.
Electric interference.
Check for improperly installed electrical options, such as light, radios, etc.
Use the F2: Snapshot mode of the Tech 2 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 suspected code or, if
you notice the reported symptom during test drive, trigger the snapshot manually.
After the snapshot has been triggered, command the Tech 2 to play back the flow of data recorded from each of the
various sensors. Sings of intermittent fault in a sensor circuit are a sudden unexplainable jump in data values out of
the normal range.
7A2-154 DIAGNOSIS (JR405E)
TCM VOLTAGE CHECK
TCM voltage check is done to check for transmission and TCM
problems which cannot be detected by self-diagnosis.
Additionally, it severs as a back-up check for self-diagnosis.
Measure the voltage drop and make a continuity test for each of
sensors, solenoids and switches.
If the voltage is within the specified range and continuity exists,
that particular area of the TCM and transmission assembly is
normal.
If voltage deviation or lack of continuity is discovered, disconnect
the applicable parts and check of them individually.
Inspection Tool
Use a circuit tester and an oscilloscope to measure voltage and
circuit continuity.
Insert the test probes from the connector wiring side. TCM
terminals are extremely small.
Wrap a piece of thin wire around the probe of tester.
This will make measurement easier.
TCM Pin Assignment
Connect to White Connector Connect to Grey Connector
No. Wire
Color Pin Name Input /
OutputConnected toMeasurement
Item Measurement
Condition StandardInspection
Point at
Trouble
A1 RED V BATT (Battery Back-up Power
Supply) Input Battery Voltage - 10 – 14.5V Related
harness
At P range 10 – 14.5V Related
harness
A2 YEL/
VIO P Range Switch Input Inhibitor switch Voltage
At other than
P range Less than 2VInhibitor
switch
At brake
stepped 10 – 14.5V Related
harness
A3 RED Brake Switch Input Brake switch Voltage At brake no
stepped Less than 2V Brake switch
At lamp OFF 10 – 14.5V Related
harness A4 PNK/
WHT 3rd Start Indicator Lamp Output 3rd start lamp Voltage
At lamp ON Less than 2V Lamp
A5 GRN K-line signal (Tech 2 serial
communication) Input/
OutputTech 2 - - - Related
harness
A6 - - - - - - - -
