DTC 15

CODE 15 ATF TEMPERATURE SENSOR

Code Chart 15:

ATF Temperature Sensor Circuit:

CIRCUIT DESCRIPTION:

The ATF temperature sensor uses a thermistor to control the signal voltage to the ECU. The ECU applies a voltage to the sensor. When the transmission fluid is cold, the sensor (thermistor) resistance is high, therefore, the ECU will see high signal voltage. As the transmission fluid warms, the sensor resistance becomes less and the voltage drops. At normal transmission operating temperature (40°C) the voltage will measure about 1.1 volts at the ECU.

TEST DESCRIPTION: Numbers below refer to the circled numbers on the diagnostic chart.

1. Verifies that approximately 2-5 volts is present at the ATF temperature sensor connector.

2. This test checks the ground side of the ATF oil temperature sensor circuit.

3. Determines if the circuit or ECU is the problem. Be sure to check the ECU connections for proper fit.

DIAGNOSTIC AIDS:

After engine is started, the ATF temperature should rise steadily to about 40°C, then stabilize. A faulty connection or an open in the YEL wire or YEL/BLU wire can result in a Code 15. An intermittent may be caused by a poor connection, rubbed through wire insulation or a wire broken inside the insulation.