NO.22 NO ENGINE BRAKING IN 1 RANGE AND 2 RANGE (2GR)[GF4AX-EL]

id0503a3805300

22
No engine braking in 1 range and 2 range (2GR)
DESCRIPTION
•  Engine speed drops to idle but the vehicle coasts when the accelerator pedal is released during cruising at medium to high speeds.
•  Engine speed drops to idle but the vehicle coasts when the accelerator pedal is released when in L range at low vehicle speed.
POSSIBLE CAUSE
1.  Clutch slippage, burnt (Coasting clutch, low and reverse brake)
•  Line pressure low
•  VSS malfunction
•  Input/turbine speed sensor malfunction
•  Sensor GND malfunction
•  Control valve body malfunction
2.  PCM does not determine that the O/D OFF switch is ON (short, or open circuit, poor operation)
•  O/D OFF switch signal malfunction
Note
•  Before following the troubleshooting steps, make sure that the Automatic Transaxle On-Board Diagnostic and Automatic Transaxle Basic Inspection are conducted.

Diagnostic procedure

STEP

INSPECTION

ACTION
1
Connect the M-MDS to DLC-2.
Turn the ignition switch to the ON position.
Select TR PID.
Is TR PID reading normal when selecting range?
Yes
Go to the next step.
No
Inspect for the TR switch adjustment.
Adjust the TR switch if necessary.
(See TRANSAXLE RANGE (TR) SWITCH ADJUSTMENT[GF4AX-EL].)
Inspect the TR switch.
Repair or replace any malfunctioning parts.
2
Do the following symptoms occur concurrently?
•  Engine flares up or slips during acceleration
•  Engine flares up or slips when shifting
Yes
Go to No.14 “ENGINE FLARES UP OR SLIPS WHEN UPSHIFTING OR DOWNSHIFTING” or No.15 “ENGINE FLARES UP OR SLIPS WHEN ACCELERATING VEHICLE”.
No
Go to the next step.
3
Inspect the value at the following PCM PIDs using the M-MDS.
(See PCM INSPECTION[L3].)
•  TSS
•  VSS
Are both PID values normal?
Yes
Go to the next step.
No
Inspect for intermittent open or short circuit in the related wiring harness and/or sensor.
4
Turn the ignition switch to the ON position.
Connect the M-MDS to DLC-2.
Simulate TCC PID for ON.
Is operating sound of the TCC control solenoid valve heard?
Yes
Replace the control valve body and repair or replace any malfunctioning parts.
(See ATX Workshop Manual (GF4AX-EL))
If any problem remains, replace the transaxle and repair or replace any malfunctioning parts.
(See ATX Workshop Manual (GF4AX-EL))
No
Inspect connection of the TCC control solenoid terminal on the ATX for bent terminals, damage, corrosion or looseness.
Inspect for stuck TCC control solenoid valve?
(See SOLENOID VALVE INSPECTION[GF4AX-EL].)
If the shift solenoids are normal, inspect for open or short circuit between the PCM terminal 1H and the TCC control solenoid valve terminal D.
5
•  Verify the test results.
―  If normal, return to the diagnostic index to service any additional symptoms.
―  If the malfunction remains, inspect the related Service Information and perform repair or diagnosis.
•  If the vehicle is repaired, troubleshooting is completed.
•  If the vehicle is not repaired or additional diagnostic information is not available, replace the PCM.