20 |
Excessive shift shock is felt when upshifting and downshifting |
DESCRIPTION |
• Excessive shift shock is felt when depressing accelerator pedal at upshifting. During cruising, excessive shift shock is felt when depressing accelerator pedal at downshifting.
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POSSIBLE CAUSE |
• Clutch slippage (low clutch, high clutch)
• Reduced line pressure
• Input/output signal malfunction (VSS, turbine sensor, throttle opening angle (CAN communication), TFT sensor, pressure control solenoid, shift solenoids A, B, C and F, oil pressure switches B, C and F).
• Control valve body malfunction (improper operation, stuck, clogged oil passage)
• Improper TCM ground
• Improper ground of GND return line in AT
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Diagnostic procedure
STEP
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INSPECTION
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ACTION
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1
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Perform the stall test. (See Stall Speed Test.)
Is the stall speed normal?
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Yes
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Go to the next step.
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No
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Repair or replace any malfunctioning parts.
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2
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Inspect the following values.
(See PCM INSPECTION.)
(See TCM INSPECTION.)
• APP1
• APP2
PCM PIDs (using WDS or equivalent)
• TP_REL
• VSS
TCM terminal voltage:
• 2G (turbine sensor)
• 2K (VSS)
Are the values normal?
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Yes
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Go to the next step.
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No
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Repair or replace any malfunctioning parts.
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3
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Disconnect the TCM connector.
Is the resistance between terminal 2U at the TCM connector and terminal J at the solenoid valve wiring harness-side connector 5.0 ohms or less?
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Yes
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Go to the next step.
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No
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Repair open circuit.
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4
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Is the resistance between ground terminal 2M or 2Q at the TCM connector and body ground 5.0 ohms or less?
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Yes
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Go to the next step.
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No
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Repair the wiring harness. Reconnect the TCM.
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5
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Inspect the TFT sensor.
Is the TFT sensor normal?
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Yes
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Go to the next step.
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No
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Replace the TFT sensor.
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6
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Stop the engine.
Disconnect the solenoid valve connector.
Measure the resistance between the following solenoid valve connector terminals.
(See SOLENOID VALVE INSPECTION.)
• Terminals E-J (shift solenoid A)
• Terminals F-J (shift solenoid B)
• Terminals H-J (shift solenoid C)
• Terminals I-J (shift solenoid F)
• Terminals K-J (pressure control solenoid)
Are the resistances normal?
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Yes
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Overhaul the control valve body and repair or replace any malfunctioning parts.
(See AT Workshop Manual.)
If the problem remains, overhaul the transmission and repair or replace any malfunctioning parts.
(See AT Workshop Manual)
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No
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Repair or replace malfunctioning parts.
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7
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Verify the test results.
• If normal, return to the diagnostic index to service any additional symptoms.
• If the malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis.
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