For a complete wiring diagram Refer to Section 8W.The EGR valve has a position sensor and the EGR position rationality is designed to make sure that the valve moves freely within its operating range. Closed valve position reference check verifies that the valve is within its allowable upper and lower limits. The EGR position rationality test looks for a sustained error relative to commanded valve position.When Monitored:Engine running.Set Condition:The EGR flow or valve movement is not what is expected. A rationality error has been detected fro the EGR Close Position Performance. Two trip fault.Possible Causes(K34) EGR SENSOR SIGNAL CIRCUIT OPEN(K34) EGR SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE(K35) EGR SOLENOID CONTROL CIRCUIT SHORTED TO VOLTAGE(K900) SENSOR GROUND CIRCUIT OPENEGR SOLENOID ASSEMBLYPCMAlways perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).1. ACTIVE DTCStart the engine.Allow the engine to reach normal operating temperature.With a scan tool, select View DTCs.It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data.Is the DTC Active or Pending at this time?YesGo To 2NoRefer to the INTERMITTENT CONDITION Diagnostic Procedure.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)2. EGR SOLENOID ASSEMBLYIgnition on, engine not running.With the scan tool, actuate the EGR Solenoid.Allow the EGR Solenoid to actuate for at least 15 seconds.Feel the EGR Solenoid for operation.Stop actuation.Does EGR Solenoid operate while actuating and then turn off when actuation test is stopped?YesGo To 3NoReplace the EGR Solenoid Assembly per Service Information.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)3. (K34) EGR SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE

Turn the ignition off.Disconnect the EGR Solenoid harness connector.Disconnect the C2 PCM harness connector.Ignition on, engine not running.Measure the voltage of the (K34) EGR Sensor Signal circuit in the EGR Solenoid harness connector.Is the voltage above 1.0 volt?YesRepair the short to voltage in the (K34) EGR Sensor Signal circuit.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE) NoGo To 44. (K35) EGR SOLENOID CONTROL CIRCUIT SHORTED TO VOLTAGE

Measure the voltage on the (K35) EGR Solenoid Control circuit at the EGR Solenoid harness connector.Is the voltage above 1.0 volt?YesRepair the short to voltage in the (K35) EGR Solenoid Control circuit.NoGo To 5 5. (K900) SENSOR GROUND CIRCUIT OPEN

Turn the ignition off.Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.Measure the resistance of the (K900) Sensor ground circuit from the EGR Solenoid harness connector to the appropriate terminal of special tool #8815.Is the resistance below 5.0 ohms?YesGo To 6NoRepair the open in the (K900) Sensor ground circuit.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE) 6. (K34) EGR SENSOR SIGNAL CIRCUIT OPEN

Measure the resistance of the (K34) EGR Sensor Signal circuit from the EGR Solenoid harness connector to the appropriate terminal of special tool #8815.Is the resistance below 5.0 ohms?YesGo To 7NoRepair the open in the (K34) EGR Sensor Signal circuit.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE) 7. PCMBefore continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.Were there any problems found?YesRepair as necessary.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoReplace and program the Powertrain Control Module per Service Information.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)