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Fault Code 14 - MAP sensor voltage too low or too high

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Code 14 indicates an electrical problem with the MAP sensor or sensor wiring. It is set when the MAP sensor voltage is above 4.9 volts or below 0.02 volts. Voltages outside of the normal range indicate an open circuit or a shorted wire or sensor.

Checking the MAP sensor wiring harness for open circuits is very easy. There is a pull-up resistor between the 5-volt reference wire and the signal wire. Disconnect the MAP sensor. Turn the key on. Connect a digital voltmeter between the 5-volt reference wire (violet and white) and the ground wire (black and light blue). The voltage should be very close to 5 volts. Then check the voltage between the signal wire (dark green and red) and the ground wire. The voltage will usually be less than the reading between 5 VREF and ground but still very close to 5 volts. Measure the continuity from the ground lead in the connector to a good chassis ground - it should be very close to 0 ohms.

If the 5.0 volt supply, the slightly lower signal voltage, or the ground is missing, trace each back to the PCM and check the voltage there (5.0V is terminal 17, signal is pin 27, and ground is pin 4). Repair any wire or the connector if a voltage is present at the PCM but not at the connector. If the voltages are not present at the PCM, disconnect the battery, remove and reconnect the PCM connector, and recheck - it is possible that the PCM connector has some corrosion on the terminals. If connector removal and replacement did not correct the problem, the PCM is probably bad.


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Last Update: August 8, 2001