DTC 25

Circuit Description
When the ignition switch is turned ON, the Sensing and Diagnostic Module (SDM) will perform tests to diagnose any malfunctions within itself. If a failure is not detected by the internal tests, the SDM will test the warning lamp circuit. The SDM constantly measures the voltage at the warning lamp output in order to determine if the lamp is ON or OFF at the correct time.

DTC 25 Will Set When
- The lamp is ON when it should be OFF
- The lamp is OFF and it should be ON.

Diagnostic Aids
When the warning lamp operates correctly, the lamp turns ON for approximately four seconds after the ignition is first switched ON, and then the lamp turns OFF. When the warning lamp continues to blink four times per second, the SDM is faulty and must be replaced.

Test Description
Steps 1 - 8 below diagnose a lamp that is ON when it is supposed to be OFF.
Steps 9 - 15 below diagnose a lamp that is OFF when it is supposed to be ON.

CAUTION: Before replacing any components, disconnect the negative battery cable. Wait one minute for the SDM capacitor to discharge. The capacitor supplies reserve power to deploy the airbags, even if the battery is disconnected Unintentional deployment of the airbags can cause injury.

CAUTION: If the Supplemental Inflatable Restraints (SIR) wiring harness is damaged, do not attempt to repair it. The repair might create a high-resistance connection which can keep the airbags from deploying when needed, resulting in injury. Replace the SIR wiring harness if it is damaged.

Steps 1 - 10:

Steps 11 - 15:

DTC 25 - Warning Lamp Failure