The HIVEC Automaic Transmission supplies the power to the solenoid valves by way of a control relay. When the TCM sets the relay to ON, the relay operates and the battery power is supplied to all the sonenoid valves. When the TCM sets the relay to OFF, all solenoid valve power is shut off and the transmission is held in the 3rd gear position. (Fail Safe Mode)
The TCM checks the A/T control relay signal by monitoring the contol signal. If, after the iginiton key is turned on, an unexpected voltage value, which is quite a bit lower than battery voltage is detected, the TCM sets this code.
Item | Detecting Condition & Fail Safe | Possible cause |
DTC Strategy | ● Check voltage range | ● Open or short in circuit ● Faulty A/T control relay ● Faulty PCM/TCM |
Enable Conditions | ● Voltage of Battery ＞9V ● Time after TCM turns on ＞0.5sec | |
Threshold value | ● Voltage ＜7V | |
Diagnostic Time | ● 0.1sec | |
Fail Safe | ● Locked in 3 rd gear.(control relay off) |
Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
Has a problem been found?
▶ Repair as necessary and then go to "Verification of Vehicle Repair" procedure
▶ Go to "Power circuit inspection" procedure
Ignition "ON" & Engine "OFF".
Disconnect the "A/T CONTROL RELAY" connector
Measure the voltage between terminal "1" of the "A/T CONTROL RELAY" harness connector and chassis ground.
Specification : Approx. B+
Is voltage within specifications?
▶ Go to "Signal circuit inspection" procedure
▶ Check that A/T-20A Fuse in engine room junction is installed or not blown.
▶ Check for Open in harness. Repair as necessary and Go to "Verification Vehicle Repair" procedure
CHECK A/T control relay harness
Ignition "OFF".
Disconnect the "A/T CONTROL RELAY" connector
Measure the voltage between terminal "4" of the "A/T CONTROL RELAY" harness connector and chassis ground.
Turn ignition switch OFF → ON
Specification: 12V is measured only for approx. 0.5sec
Is voltage within specifications?
▶ Go to "Check Supplying Power to solenoid valve" procedure
▶ Check for open in harness. Repair as necessary and Go to "Verification Vehicle Repair" procedure
▶ If signal circuit is OK,Substitute with a known-good PCM/TCM and check for proper operation. If the problem is corrected, replace PCM/TCM and then go to
CHECK Supplying Power to solenoid valve harness
Ignition "OFF".
Disonnect the "A/T CONTROL RELAY" and PCM/TCM connector
Measure the resistance between terminal "3" of the "A/T CONTROL RELAY" harness connector and terminal "2, 3" of the PCM/TCM harness connector
Specification : Approx. 0 Ω
Is resistance within specifications?
▶ Go to "Ground circuit inspection" procedure
▶ Check for Open in C-41 joint connector
▶ Check for open in harness. Repair as necessary and Go to "Verification Vehicle Repair" procedure
Ignition "OFF".
Connect the "A/T CONTROL RELAY" connector
Measure the resistance between terminal "2" of the "A/T CONTROL RELAY" harness connector and chassis ground
Specification : Approx. 0 Ω
Is resistance within specifications?
▶ Go to "Component inspection" procedure
▶ Check for open in harness. Repair as necessary and Go to "Verification Vehicle Repair" procedure
Ignition "OFF".
Remove "A/T CONTROL RELAY"
Measure the resistance between each teminal of the sensor
Specification:
Item | Termianl No | |
Resistance | 1(red) - 3(pink) | INFINITE |
2(black) - 4(pinl) | ||
supply(B+) to number 4 and supply (B-) to number 2. | 1(red) - 3(pink) | 0 Ω |
Is resistance with in specification?
▶ Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.
▶ Replace ATM CONTROL RELAY and then go to "Verification of Vehicle Repair" procedure.
After a repair, it is essential to verify that the fault has been corrected.
Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode.
Using a scantool, Clear DTC.
Operate the vehicle within DTC Enable conditions in General information.
Are any DTCs present ?
▶ Go to the applicable troubleshooting procedure.
▶ System performing to specification at this time.
