P057

Diagnostic Trouble Code Chart P057:

Powertrain Control Module (PCM) Sensor Circuit:

CIRCUIT DESCRIPTION
The transaxle temperature sensor is a thermistor, or variable resistor, whose resistance varies based on its temperature. As the temperature of the sensor increases, its resistance decreases. A high transaxle temperature will result in low signal voltage on CKT 585. Code P057 sets when the Powertrain Control Module (PCM) sees a transaxle temperature sensor reading of 148°C (298°F) or greater (0.08 volt or less).

TEST CONDITION
Test continuously.

FAILURE CONDITION
Transaxle temperature sensor value is 148°C (298°F) or greater for 5 seconds.

ACTION TAKEN
1. PCM turns "ON" the Malfunction Indicator Lamp (MIL) (Service Engine Soon) message.
2. PCM will substitute engine coolant temperature value for transaxle temperature until engine coolant temperature reaches 105°C (221°F) then transaxle will be set to hot mode operation
3. Transaxle shift adapts are maintained at current levels.
4. Garage shift adapts are maintained at current level.

NOTES ON FAULT TREE
1. If the Transaxle Temperature Sensor is shorted, PCM data PD77 should read 148°C or more. If the parameter does not show this, then the sensor and wiring are OK.
2. Checking for CKT 585 shorted. If the parameter value stays at -28°C or greater with connector C129 unplugged, the short is in CKT 585 between connector C129 pin "M" and PCM terminal "1B14."
3. Checking for a short to ground on CKT 585 inside the transaxle. If wire OK, replace the shorted transaxle temperature sensor.