Theory Of Operation

The Charge Air Cooler Temperature (CAC) Sensor and the Boost Pressure Sensor are combined in one sensor. This combination sensor is called the Temperature/Manifold Absolute Pressure (TMAP) Sensor. It is located on the EGR Airflow Throttle Control Valve on the Pickup. For the Cab and Chassis, it is located on the Intake Manifold. The Cab and Chassis version also receives the Intake Air Temperature signal. The Pickup still has a separate Intake Air Temperature (IAT) Sensor. The Boost Pressure Sensor is used to measure pressure in the intake manifold. The Powertrain Control Module (PCM) provides a 5-Volt supply and sensor ground for the TMAP Sensor. The TMAP Sensor provides a signal back to the PCM on the TMAP Sensor Signal circuit. The PCM will detect a low signal voltage at operating conditions such as during an idle or a deceleration. The PCM will detect a high signal voltage during high engine load operating conditions. At key on, the readings for the TMAP Sensor, Exhaust Gas Pressure Sensor, and Barometric Pressure Sensor are compared.