25 Vacuum Leak Found - (P 1299)

25 VACUUM LEAK FOUND - (P 1299)

The Powertrain Control Module (PCM) monitors inputs of the Manifold Absolute Pressure (MAP) sensor, Throttle Position Sensor (TPS), Engine Coolant Temperature (ECT) sensor, A/C switch, power steering switch, and the generator. The PCM then calculates an expected MAP sensor reading and compares to the present MAP sensor reading. If the calculated MAP sensor value does not match the present MAP sensor value, the PCM assumes additional air is entering the engine combustion chamber. The PCM illuminates the MIL and stores the DTC if the calculated MAP sensor value does not match the present MAP sensor value.

The Vacuum Leak Found malfunction could possibly be caused by problems with any of the following components:

- Throttle body or gasket (vacuum leak)
- Intake manifold (cracked)
- Brake booster diaphragm (vacuum leak) PCV valve, etc. (vacuum leak)