P1723
DTC P1723 A/T CONTROL RELAYGENERAL DESCRIPTION
The HIVEC Automatic 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 solenoid 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)
DTC DESCRIPTION
The TCM checks the A/T control relay signal by monitoring the control signal. If, after the ignition key is turned on, an unexpected voltage value, which is quite a bit lower than battery voltage is detected, the TCM sets this code.
DTC DETECTING CONDITION
DTC DETECTING CONDITION:
SCHEMATIC DIAGRAM
SCHEMATIC DIAGRAM:
MONITOR SCAN TOOL DATA
1. Connect scan tool to data link connector (DLC).
2. Ignition "ON" & Engine "OFF".
3. Monitor the "A/T CON. RELAY VOLT" parameter on the scan tool.
Specification: Approximately B+
Is A/T RELAY VOLT within specifications?
YES - Fault is intermittent caused by poor contact in the sensor's and/or PCM/TCM's connector or was repaired and PCM/TCM memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.
NO - Go to "W/Harness Inspection" procedure.
TERMINAL & CONNECTOR INSPECTION
1. 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.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?
YES - Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
NO - Go to "Power Circuit Inspection" procedure.
POWER SUPPLY CIRCUIT INSPECTION
1. Ignition "ON" & Engine "OFF".
2. Disconnect the "A/T CONTROL RELAY" connector.
3. Measure the voltage between terminal "1" of the "A/T CONTROL RELAY" harness connector and chassis ground.
Specification: Approximately B+
Is voltage within specifications?
YES - Go to "Signal Circuit Inspection" procedure.
NO - 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 of Vehicle Repair" procedure.
SIGNAL CIRCUIT INSPECTION
1. CHECK A/T control relay harness
1. Ignition "OFF".
2. Disconnect the "A/T CONTROL RELAY" connector.
3. Measure the voltage between terminal "4" of the "A/T CONTROL RELAY" harness connector and chassis ground.
4. Turn ignition switch OFF - ON
Specification: 12 V is measured only for approximately 0.5 sec
Specification:
5. Is voltage within specifications?
YES - Go to "Check Supplying Power to Solenoid Valve" procedure.
NO - Check for open in harness. Repair as necessary and Go to "Verification of Vehicle Repair" procedure.
If signal circuit is OK, Substitute with a known-good PCM/TCM and check for proper operation. If the problem is.
2. CHECK Supplying Power to solenoid valve harness
1. Ignition "OFF".
2. Disconnect the "A/T CONTROL RELAY" and PCM/TCM connector.
3. Measure the resistance between terminal "3" of the "A/T CONTROL RELAY" harness connector and terminal "7, 19" of the PCM/TCM harness connector.
Specification: Approximately 0 Ohms
Specification:
4. Is resistance within specifications?
YES - Go to "Ground Circuit Inspection" procedure.
NO - Check for Open in C-41 joint connector. Check for open in harness. Repair as necessary and Go to "Verification of Vehicle Repair" procedure.
GROUND CIRCUIT INSPECTION
1. Ignition "OFF".
2. Connect the "A/T CONTROL RELAY" connector.
3. Measure the resistance between terminal "2" of the "A/T CONTROL RELAY" harness connector and chassis ground.
Specification: Approximately 0 Ohms
Specification:
4. Is resistance within specifications?
YES - Go to "Component Inspection" procedure.
NO - Check for open in harness. Repair as necessary and Go to "Verification of Vehicle Repair" procedure.
COMPONENT INSPECTION
1. Ignition "OFF".
2. Remove "A/T CONTROL RELAY".
3. Measure the resistance between each terminal of the sensor.
Specification:
Specification:
4. Is resistance within specifications?
YES - 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.
NO - Replace ATM CONTROL RELAY as necessary and then go to "Verification of Vehicle Repair" procedure.
VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1. Connect scan tool and select "Diagnostic Trouble Codes (DTCs)" mode.
2. Using a scan tool, Clear DTC.
3. Operate the vehicle within DTC Enable conditions in General information.
4. Are any DTCs present?
YES - Go to the applicable troubleshooting procedure. Transmission
NO - System performing to specification at this time.