DTC 25

Code 25 Diagnostic Chart:

Code 25 Circuit Diagram:

CIRCUIT DESCRIPTION:

During cold operation the ECM grounds the circuit, energizing the solenoid and permitting air to go to the exhaust and catalytic converter. During off idle, the air is diverted to the atmosphere when the solenoid is de-energized by the ECM. When the engine is started and is already at operating temperature, air is directed to the exhaust momentarily then to the atmosphere.

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

1. Checks for proper operation of solenoid.

2. Checks for grounded circuit 429 or ECM.

3. Checks to see if voltage is available to circuit.

DIAGNOSTIC AIDS:

Verify clean tight connections at ECM terminal "13" and at the VSV Solenoid. If Code 25 is intermittent, Testing and Inspection