DTC 63

Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION
The Manifold Absolute Pressure (MAP) Sensor responds to changes in manifold pressure (vacuum). The Electronic Control Module (ECM) receives this information as a signal voltage that will vary from about 1 to 1.5 volt at idle (high vacuum) and 4 to 4.5 volts at wide open throttle (low vacuum).

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

1. Code 63 will set, with Engine Running:

^ Manifold pressure greater than 75.3 kPa (A/C "OFF") 81.2 kPa (A/C "ON")
^ Throttle angle less than 2%
^ Conditions met for 2 seconds. Engine misfire or a low unstable idle may set Code 63.

2. With the MAP sensor disconnected, the ECM should see a low voltage if the ECM and wiring is OK.

DIAGNOSTIC AIDS
If idle is rough or unstable See Diagnosis By Symptoms, for items which can cause an unstable idle. An open in CKT 455 or the connection will result in a Code 63. Ignition "ON" engine "OFF", voltages should be within the values shown in the table on the chart. Also C-Charts Component Testing / Chart C-1D can be used to test the MAP sensor. Chart C-1D Manifold Absolute Pressure (MAP) Output Check