P1186-INLET PRESSURE SENSOR SIGNAL VOLTAGE TOO LOW

For a complete wiring diagram Refer to Section 8W

When Monitored:
With the ignition on.
Set Condition:
The Inlet Pressure Sensor signal is below 0.25 volt for 2.0 seconds.

Possible Causes

INTERMITTENT CONDITION

INLET PRESSURE SENSOR SIGNAL CIRCUIT OPEN

INLET PRESSURE SENSOR 5 VOLT SUPPLY

INLET PRESSURE SENSOR

INLET PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO GROUND

INLET PRESSURE SENSOR SIGNAL AND GROUND CIRCUITS SHORTED TOGETHER

ENGINE CONTROL MODULE

Diagnostic Test

1. CHECKING FOR CURRENT DTC

NOTE: If the ECM detects and stores a DTC, the ECM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the scan tool at the same time the DTC is displayed.

NOTE: Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for an active DTC.

NOTE: Ensure all turbocharger inlet and outlet tubes are connected properly, without damage and restriction before continuing with this test.

Turn the ignition on.
With the scan tool, erase ECM DTCs.
Cycle the ignition key on and off several times, leaving the key on for at least 10 seconds at a time.
With the scan tool, read ECM DTCs.

Did this DTC set again?

Yes

Go To 2

Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

2. INLET PRESSURE SENSOR 5 VOLT SUPPLY VOLTAGE

Turn the ignition off.
Disconnect the Inlet Pressure Sensor harness connector.
Turn the ignition on.
Measure the voltage between ground and the Inlet Pressure Sensor 5 Volt Supply circuit.

Is the voltage above 4.8 volts?

Yes

Go To 3

Repair the Inlet Pressure Sensor 5 Volt Supply circuit for an open.
Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

3. INLET PRESSURE SENSOR SIGNAL CIRCUIT OPEN

Turn the ignition off.
Disconnect the ECM harness connectors.
Measure the resistance of the Inlet Pressure Sensor Signal circuit.

Is the resistance below 10.0 ohms?

Yes

Go To 4

Repair the Inlet Pressure Sensor Signal circuit for an open.
Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

4. INLET PRESSURE SENSOR SIGNAL AND GROUND CIRCUITS SHORTED TOGETHER

Measure the resistance between the Inlet Pressure Sensor Signal circuit and Inlet Pressure Sensor Ground circuit.

Is the resistance above 1000 ohms?

Yes

Go To 5

Repair the Inlet Pressure Sensor Signal circuit for a short to the Inlet Pressure Sensor Ground circuit.
Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

5. INLET PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO GROUND

Measure the resistance between ground and the Inlet Pressure Sensor Signal circuit.

Is the resistance above 1000 ohms?

Yes

Go To 6

Repair the Inlet Pressure Sensor Signal circuit for a short to ground.
Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

6. INLET PRESSURE SENSOR

Connect a jumper wire between the Inlet Pressure Sensor Signal and Inlet Pressure Sensor 5 Volt Supply circuits.
Turn the ignition on.
With the scan tool, read the Inlet Pressure Sensor voltage.

Is the voltage above 4.5 volts?

Yes

Replace the Inlet Pressure Sensor.

Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

Replace and program the Engine Control Module in accordance with the Service Information.
Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).