ELECTRICAL SYSTEM TESTS, INSPECTIONS, AND ADJUSTMENTS - CONTINUED
ENGINE PRESSURE SENSOR OPEN OR SHORT CIRCUIT TEST
N OT E
Use this procedure to troubleshoot anysuspect problems with following sensors:
Fuel pressure sensor.
Engine oil pressure sensor.
Atmospheric pressure sensor.
Right turbo inlet pressure sensor.
Intake manifold pressure sensor.
Use this procedure to troubleshootsystem when one of following diagnostic codes is active or eas-
94-03 Fuel Pressure Open/Short to +Batt
94-04 Fuel Pressure Short to Ground
100-03 Engine Oil Pressure Open/Short to +Batt
100-04 Engine Oil Pressure Short to Ground
274-03 Atmospheric Pressure Open/Short to +Batt
274-04 Atmospheric Pressure Short to Ground
275-03 Right Turbo Inlet Pressure Open/Short to +Batt
275-04 Right Turbo Inlet Pressure Short to Ground
1785-03 Intake Manifold Pressure Sensor Voltage High
1785-04 Intake Manifold Pressure Sensor Voltage Low
5V sensor supply provides power to all 5V sens rs. ECM supplies 5.0 ± 0.2 VDC to terminal A of
each sensor connector.
Sensor return from ECM connector goes to terminal B of each sensor connector.
Sensor supply is output short crcuit protected. A short circuit to battery will not damage circuit
ECM continuously outputs a pull-up volta e on circuit for sensor signal wire.
ECM uses this pull-up voltage to detect problem in signal circuit.
When ECM detects presence of voltage that is ab ve a threshold on signal circuit, ECM will gen-
erate an 03 diagnostic code for sensor.
If sensor is disconnected at sensor connector, pr sence of pull-up voltage at sensor connector indi-
cates that wires from sensor connector to ECM are OK.
If sensor is disconnected at sensor connector, abence of pull-up voltage at sensor connector indi-
cates problem in signal wire.
If sensor is disconnected at sensor connectorand voltage at sensor connector is different from
pull-up voltage, signal wire may be shorted to another wire in harness.