Code P059, Open Transaxle Temperature Sensor Circuit: Action

PCM turns on MIL. PCM substitutes coolant temperature value for transaxle temperature until coolant temperature reaches 221°F (105°C) then sets transaxle to hot mode operation.

1. With transaxle temperature sensor or wiring open, PCM data PD77 will read -31°F (-35°C) or less. If parameter does not show this, sensor and circuit are okay.
2. Check for open in circuit No. 585 between PCM and sensor connector. If PCM data PD77 reads 298-303°F (148-151°C) with sensor terminal "F" jumpered to ground, circuit No. 585 and PCM are okay.
3. Checks circuit No. 808 for open to PCM terminal connector.
4. Checks PCM's ability to recognize low voltage on PCM terminal 3F12 (transaxle temperature sensor input). If grounding PCM terminal 3F12 caused PCM data PD1 to read 298-303°F (148-151°C), check for open in circuit No. 585 between PCM and sensor connector.
5. Checks for an open transaxle temperature sensor.

Fig 1: Code P059 Schematic (DeVille)

Courtesy of GENERAL MOTORS CORP.

Fig 2: Code P059 Flow Chart (DeVille)

Courtesy of GENERAL MOTORS CORP.