Powertrain Controls - ECM/PCM

DTC 32:

MAP Sensor Circuit:

CIRCUIT DESCRIPTION:
The Manifold Absolute Pressure (MAP) Sensor measures the change in the intake manifold pressure (vacuum). The ECM applies 5.0 volts to the MAP sensor. The change in the pressure, that results from engine load and rpm changes, is converted into a voltage input that is monitored by the ECM. A low voltage reading at the ECM indicates low manifold pressure, and a high voltage reading at the ECM indicates high manifold pressure. DTC 32 will set if the following condition is met for 0.2 seconds: High voltage input at the ECM indicating intake manifold pressure above 840 mmHg.

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

1. This step checks the LT GRN/RED wire for an open, a short to voltage and a faulty ECM. Under normal conditions the LT GRN/RED wire should carry a little less than 5.0 volts. A short to 5.0 volts or B+ will cause DTC 32 to set.

2. This step checks for an open LT GRN/BLK wire, poor connection at the MAP sensor or ECM and for a faulty MAP sensor or ECM.

DIAGNOSTIC AIDS:
Check for a leaking vacuum hose to MAP sensor.

An intermittent may be caused by a poor connection rubbed through wire insulation or a wire broken inside the insulation, Inspect ECM harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wire connection and damaged harness.