Circuit Description

Manifold Absolute Pressure (MAP) sensor responds to changes in intake manifold pressure. PCM supplies a 5-volt reference and ground signals to MAP sensor. MAP sensor provides a signal to PCM relative to pressure changes in manifold. A low MAP pressure (high vacuum) will generate a low MAP sensor signal voltage. A high MAP pressure (low vacuum) will generate a high MAP sensor signal voltage. PCM predicts a MAP sensor value based on throttle position and engine speed, then compares this value to actual MAP sensor input. DTC will set when MAP sensor value does not closely match predicted value for 5 seconds.

For duplication of DTC, ensure:

• No TP sensor DTCs are set.
• Engine speed is between 1000-4000 RPM on Eldorado and Seville.
• Engine speed is between 1600-4000 RPM on DeVille.
• Throttle angle is steady.
• IAC, TCC and EGR is steady.
• A/C compressor clutch is steady.
• Vehicle brakes not applied.