Dodge Ram Truck 1500-2500-3500. Manual — part 1041

P0108-INLET AIR Pressure Sensor Voltage Too high (CONTINUED)

For the Engine circuit diagram (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CON-
TROL MODULE - SCHEMATIC - ELECTRICAL)

For a complete wiring diagram Refer to Section 8W.

•

When Monitored:
With the ignition on and battery voltage greater than 10.4 volts.

•

Set Condition:
The circuit voltage to the ECM is above a calibrated threshold for a certain period of time.

Possible Causes

OTHER DTC’S PRESENT

INLET AIR PRESSURE SENSOR

INLET AIR PRESSURE SENSOR (K616) SIGNAL CIRCUIT SHORTED TO VOLTAGE

INLET AIR SENSOR (K668) 5-VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE

(K616) SIGNAL CIRCUIT SHORTED TO (K668) 5-VOLT SUPPLY

(K690) RETURN CIRCUIT OPEN

ECM

INTERMITTENT CONDITION

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)

Diagnostic Test

1.

OTHER DTC’S PRESENT

Ignition on, engine not running.

With the scan tool, read DTCs.

Do you have multiple DTC’s?

Yes

>> Repair other DTC’s first.

Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)

No

>> Go To 2

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ENGINE - ELECTRICAL DIAGNOSTICS - DIESEL

DR/DH

P0108-INLET AIR Pressure Sensor Voltage Too high (CONTINUED)

2.

CHECKING (K668) 5-VOLT SUPPLY CIRCUIT AND THE (K690) RETURN CIRCUIT

Disconnect the Inlet Air Pressure sensor harness connector.

Measure the voltage between the (K668) 5-volt supply circuit and
(K690) return circuit of the Inlet Air Pressure sensor harness connec-
tor.

Is the voltage between 4.5 and 5.5 volts?

Yes

>> Go To 3

No

>> Go To 4

3.

INLET AIR PRESSURE SENSOR

While monitoring scan tool, use a jumper wire to connect the (K690)
Return circuit to the (K616) signal circuit at the Inlet Air Pressure sen-
sor harness connector.

Does the scan tool show a P0107 Inlet Air Pressure Sensor Low
DTC.

Yes

>> Replace the Inlet Air Temperature/Pressure sensor.

Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)

No

>> Go To 4

DR/DH

ENGINE - ELECTRICAL DIAGNOSTICS - DIESEL

9 - 1087

P0108-INLET AIR Pressure Sensor Voltage Too high (CONTINUED)

4.

INLET AIR SENSOR (K616) SIGNAL CIRCUIT SHORTED TO VOLTAGE

Disconnect the ECM harness connectors.

NOTE: Check connectors - Clean/repair as necessary.
Measure the voltage between the (K616) signal circuit of the Inlet Air
Pressure sensor connector and battery negative.

Is the voltage less than 1 volt?

Yes

>> Go To 5

No

>> Repair or replace short to voltage.

Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)

5.

(K668) 5-VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE

Measure the voltage between the (K668) 5-volt supply circuit of the
sensor connector and battery negative.

Is the voltage less than 1 volt?

Yes

>> Go To 6

No

>> Repair the short to voltage or replace the harness.

Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)

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ENGINE - ELECTRICAL DIAGNOSTICS - DIESEL

DR/DH

P0108-INLET AIR Pressure Sensor Voltage Too high (CONTINUED)

6.

SIGNAL CIRCUIT SORTED TO (K668) 5-VOLT SUPPLY

Turn the ignition off.

Measure the resistance between the (K616) signal circuit and the
(K668) 5-volt supply circuit of the Inlet Air Pressure sensor harness
connector.

Is the resistance less than 10 Ohms?

Yes

>> Go To 7

No

>> Repair or replace the shorted wiring harness.

Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)

7.

(K690) RETURN CIRCUIT OPEN

Disconnect the ECM harness connector.

Check connectors - Clean/repair as necessary.

Measure the resistance between the (K690) return circuit in the Inlet
Air Pressure sensor harness connector with the (K690) return circuit in
the ECM harness connector.

Is the resistance less than 10 Ohms?

Yes

>> Go To 8

No

>> Repair or replace the Engine harness.

Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)

DR/DH

ENGINE - ELECTRICAL DIAGNOSTICS - DIESEL

9 - 1089