P0890
DTC P0890 AT RELAY - LOW CIRCUITCOMPONENT LOCATION
Refer to DTC P0885. P0885
GENERAL DESCRIPTION
The automatic transmission supplies power to the solenoid valves by way of a control relay. When the PCM sets the relay to ON, the relay operates and the battery power is supplied to all the solenoid valves. When the PCM 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 PCM checks the A/T control relay signal by monitoring the control signal. If the voltage applied to A/T solenoids is lower than 0.5 V, the PCM sets this code.
DTC DETECTING CONDITION
DTC DETECTING CONDITION:
MONITOR SCAN TOOL DATA
Refer to DTC P0885. P0885
TERMINAL & CONNECTOR INSPECTION
Refer to DTC P0885. P0885
POWER SUPPLY CIRCUIT INSPECTION
1. Ignition ON & Engine OFF.
2. Disconnect the A/T CONTROL RELAY connector.
3. Measure the voltage between the power terminal of the A/T CONTROL RELAY in the engine room relay box and chassis ground.
Specification: Approximately B+
Specification:
4. 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 ATM CONTROL RELAY connector.
3. Measure the voltage between terminal 60 of the PCM harness connector A and chassis ground.
4. Turn ignition switch OFF -ON.
Specification: 12 V is measured only for approximately 0.5 sec
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 and check for proper operation. If the problem is corrected, replace PCM and then go to Verification of Vehicle Repair procedure.
2. CHECK supplying power to solenoid valve harness
1. Ignition OFF.
2. Disconnect the ATM CONTROL RELAY and PCM connector.
3. Measure the resistance between the terminal shown of the A/T CONTROL RELAY in the engine room relay box and terminal 20 of the PCM harness connector A.
Specification: Approximately 0 Ohms
Specification:
4. Is resistance within specifications?
YES > Go to Ground circuit inspection procedure.
NO > Check for open in harness. Repair as necessary and go to Verification of Vehicle Repair procedure.
GROUND CIRCUIT INSPECTION
1. Ignition OFF.
2. Disconnect A/T CONTROL RELAY connector.
3. Measure the resistance between the terminal shown of the A/T CONTROL RELAY in the engine room relay box 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: Infinite except between those two terminals below
Specification:
4. Is resistance with in specification?
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 and then go to Verification of vehicle repair procedure.
VERIFICATION OF VEHICLE REPAIR
Refer to DTC P0885. P0885