DTC 63

Chart:

Map Circuit:

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) to 4-4.5 volts at wide open throttle (low vacuum).

TEST DESCRIPTION:
Numbers below refer to circled numbers on the diagnostic chart.
1. Code 63 will set when:
- 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 - NO TROUBLE CODE STORED," 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 CHART C-1D can be used to test the MAP sensor. Chart C-1D Manifold Absolute Pressure (MAP) Output Check