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P00F5




DTC P00F4-P00F6

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC P00F4
- Intake Air Humidity Sensor Circuit Low Voltage

DTC P00F5
- Intake Air Humidity Sensor Circuit High Voltage

DTC P00F6
- Intake Air Humidity Sensor Circuit Erratic

Diagnostic Fault Information






Typical Scan Tool Data






Circuit/System Description

The sensors listed below are integrated within the humidity sensor:

* Intake Air Temperature (IAT) sensor 1

* Humidity sensor

The humidity sensor measures the ambient humidity of the air in the sensor bore. The duty cycle signal varies with intake air humidity and is displayed by the scan tool as %. The ECM applies 5 V to the circuit. The signal circuit is shared by the humidity sensor and the intake air temperature (IAT) sensor 1. Ignition voltage and ground circuits are also supplied to the multifunction intake air sensor's internal circuits for these sensors:

* IAT sensor 1

* Humidity sensor

Conditions for Running the DTCs

* The engine is running for longer than 10 s.

* The battery voltage is more than 11 V.

* DTC P00F4, P00F5, and P00F6 run continuously when the above conditions are met.

Conditions for Setting the DTCs

P00F4

The ECM detects that the humidity sensor signal is less than or equal to 5 % for greater than 5 s.

P00F5

The ECM detects that the humidity sensor signal is greater than or equal to 95 % for greater than 5 s.

P00F6

The ECM detects that the humidity sensor signal is intermittent or has abruptly changed over a period of time greater than 5 s.

Action Taken When the DTC Sets

DTCs P00F4, P00F5, P00F6 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTCs P00F4, P00F5, P00F6 are Type B DTCs.

Diagnostic Aids

* The following 2 functions of the (8 Pin) Multifunction Intake Air Sensor (IAT sensor 1) are used by the ECM:

- Intake Air Humidity

- Intake Air Temperature (IAT sensor 1)

* The (8 Pin) Multifunction Intake Air Sensor (IAT sensor 1) is placed in the air stream ahead of the (5 Pin) Mass Air Flow/Intake Air Temperature Sensor (IAT sensor 2). They are both mounted to the air cleaner cover.

* The Intake Air Humidity sensor signal and the IAT sensor 1 signal are sent to the ECM on the same circuit. If the Intake Air Humidity parameter displays the value: 0 %, and there are also IAT sensor 1 DTCs, check for a circuit problem.

* The Intake Air Humidity Signal parameter displays the measured humidity within the air intake system and may differ from atmospheric humidity measured outside the air intake system.

* With the ignition ON, the engine OFF; if the engine is cold, a properly functioning humidity sensor will gradually increase the scan tool Intake Air Humidity Signal parameter. This is due to the heat that is generated by the sensor heating elements.

Reference Information

Schematic Reference

Engine Controls Schematics [1][2]Electrical Diagrams

Connector End View Reference

Component Connector End Views 1-2 Shift Solenoid (SS) Valve (M30)

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References Control Module References for scan tool information

Special Tools

* J 38522 - Variable Signal Generator

* For equivalent regional tools, refer to Special Tools Tools and Equipment.

Circuit/System Verification

Note:

* To minimize the effects of residual engine heat and sensor internal heating elements, perform Steps 1 and 2 of this verification procedure only if the ignition has been OFF for 8 hours or more.

* The vehicle sitting in direct sun light or having the block heater ON will skew the results.

1. Ignition ON.

2. Verify the following scan tool parameters are within 25°C (45°F) of each other.

* Start-Up IAT Sensor 1

* IAT Sensor 2

* Start-Up ECT

• If not within the specifications
Refer to Circuit/System Testing.

• If within the specifications

3. Engine running.

4. Verify the scan tool Intake Air Humidity parameter is between 5 and 90 %.

• If not within the specifications
Refer to Circuit/System Testing.

• If within the specifications

5. Operate the vehicle within the conditions for running the DTC to verify that the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.

6. Verify the DTCs do not set.

• If any of the DTCs set
Refer to Circuit/System Testing.

• If none of the DTCs set

7. All OK

Circuit/System Testing

Note:

* You must perform the Circuit/System Verification before proceeding with the Circuit/System Testing.

* You must perform the Diagnostic Repair Verification after completing the Circuit/System Testing.

1. Ignition OFF, disconnect the harness connector at the (8 Pin) B75C Multifunction Intake Air Sensor (Humidity Sensor).

2. Ignition OFF, all vehicle systems OFF, test for less than 2 ohms between the ground circuit terminal 7 and ground.

• If 2 ohms or greater

1. Ignition OFF.

2. Test for less than 2 ohms in the ground circuit end to end.

• If 2 ohms or greater, repair the open or high resistance in the circuit.

• If less than 2 ohms, repair the open/high resistance in the ground connection.

• If less than 2 ohms

3. Ignition ON, verify a test lamp illuminates between the ignition voltage circuit terminal 5 and ground.

• If the test lamp does not illuminate and the circuit fuse is good

1. Ignition OFF, remove the test lamp and remove the fuse for the ignition voltage circuit.

2. Test for less than 2 ohms in the ignition voltage circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse.

• If the test lamp does not illuminate and the circuit fuse is open

1. Ignition OFF, remove the test lamp and remove the fuse for the ignition voltage circuit.

2. Test for infinite resistance between the ignition voltage circuit and ground.

• If less than infinite resistance, repair the short to ground on the circuit.

• If infinite resistance

3. Test for greater than 2 ohms between the ignition voltage circuit terminal 5 and ground.

• If less than 2 ohms, repair the short to ground on the circuit.

• If greater than 2 ohms, test all the components connected to the circuit and repair or replace as necessary.

• If the test lamp illuminates

4. Ignition ON, test for 4.8-5.2 V between the intake air humidity signal circuit terminal 8 and ground.

• If less than 4.8 V

1. Ignition OFF, disconnect the X3 harness connector at the K20 Engine Control Module.

2. Test for infinite resistance between the signal circuit and ground.

• If less than infinite resistance, repair the short to ground on the circuit.

• If infinite resistance

3. Test for less than 2 ohms in the signal circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, replace the K20 Engine Control Module.

• If greater than 5.2 V

Note: If the signal circuit is shorted to a voltage the engine control module or the sensor may be damaged.

1. Ignition OFF, disconnect the X3 harness connector at the K20 Engine Control Module.

2. Ignition ON, test for less than 1 V between the signal circuit and ground.

• If 1 V or greater, repair the short to voltage on the circuit.

• If less than 1 V, replace the K20 Engine Control Module.

• If between 4.8-5.2 V

5. Ignition OFF, connect the leads of the J 38522 - Variable Signal Generator as follows:

* Red lead to the signal circuit terminal 8 at the harness connector

* Black lead to ground

* Battery voltage supply lead to B+

6. Set the J 38522 - Variable Signal Generator to the following specifications.

* Signal switch to 5 V

* Frequency switch to 250 Hz

* Duty Cycle switch to 50 % (Normal)

7. Ignition ON, verify the scan tool Intake Air Humidity parameter is between 45-55 %.

• If not between 45-55 %.
Replace the K20 Engine Control Module.

• If between 45-55 %.

8. Test or replace the (8 Pin) B75C Multifunction Intake Air Sensor (Humidity Sensor).

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

* Mass Airflow Sensor with Intake Air Temperature Sensor Replacement (5 Pin) Mass Airflow Sensor with Intake Air Temperature Sensor Replacement (5 Pin)Mass Airflow Sensor with Intake Air Temperature Sensor Replacement (8 Pin) Mass Airflow Sensor with Intake Air Temperature Sensor Replacement (8 Pin)
for (8 Pin) Multifunction Intake Air Sensor replacement

* Perform the scan tool Diesel Particulate Filter (DPF) Regeneration Enable Diesel Particulate Filter (DPF) Regeneration Enable procedure if the scan tool DPF Soot Mass is less than 30 g. If the scan tool DPF Soot Mass is greater than 30 g, perform the Diesel Particulate Filter (DPF) Service Regeneration Diesel Particulate Filter (DPF) Service Regeneration.

* Control Module References Control Module References for Engine Control Module replacement, programming, and setup

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