| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. | 
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. | 
| • | Diagnostic Procedure Instructions provide an overview of each diagnostic category. | 
Circuit  | Short to Ground  | High Resistance  | Open  | Short to Voltage  | 
|---|---|---|---|---|
IA Flow Valve 5-Volt Reference Voltage  | P0642  | P02E9  | P02E8  | P0336, P0643  | 
IA Flow Valve Sensor Signal  | P02E8  | P02E7  | P02E8  | P02E9  | 
IA Flow Valve Low Reference  | --  | P02E7  | P02E9  | --  | 
IA Flow Valve Motor Control 1  | P02E0  | --  | P02E0  | P02E0  | 
IA Flow Valve Motor Control 2  | P02E0  | --  | P02E0  | P02E0  | 
The intake air (IA) valve is a normally open valve and is only operated during a DPF regeneration. The position of the IA valve is controlled by the engine control module (ECM). The IAF Valve system uses a position sensor located within the valve assembly to monitor the position of the valve. The position sensor has the following circuits:
| • | 5-volt reference circuit | 
| • | Low reference circuit | 
| • | Signal circuit | 
The IAF valve uses a motor to move the valve to a closed position and spring tension returns it to the open position. The motor has the following circuits:
| • | Motor control 1 circuit | 
| • | Motor control 2 circuit | 
| • | DTCs P0698 or P0699 are not set. | 
| • | The ignition is ON. | 
| • | DTCs P02E8 and P02E9 run continuously. | 
The IAF valve position is less than 0.102 volt for 3 seconds.
The IAF valve position is greater than 4.75 volts for 3 seconds.
| • | DTCs P02E8 and P02E9 are Type B DTCs. | 
| • | Diesel particulate filter (DPF) regeneration is inhibited. | 
DTCs P02E8 and P02E9 are Type B DTCs.
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
| ⇒ | If greater than 5 ohms, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM. | 
| ⇒ | If less than 4.8 volts, test 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM. | 
| ⇒ | If greater than 5.2 volts, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM. | 
| ⇒ | If greater than 0.1 volt, test the signal circuit terminal E for a short to voltage. If the circuit tests normal, replace the ECM. | 
| ⇒ | If less than 4.8 volts, test the IA valve signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM. | 
| • | Control Module References for ECM replacement, setup and programming |