Diagnostic Test

1) DTC IS ACTIVE
Start the engine and allow it to reach normal operating temperature.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.

NOTE: Diagnose and repair any system voltage or sensor supply voltage DTCs before continuing with this test.

With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes
1. Go to 2).
No
1. Refer to *CHECKING FOR AN INTERMITTENT DTC .
2) (F856) 5 VOLT SUPPLY CIRCUIT VOLTAGE

Fig 1: Measuring The Voltage Of The 5 Volt Supply Circuit In The EGR Valve Assembly Harness Connector
Courtesy of CHRYSLER LLC

Turn the ignition off.

Disconnect the EGR Valve Assembly connector.

Turn the ignition on.

Measure the voltage of the (F856) 5 Volt Supply circuit in the EGR Valve Assembly harness connector.

Is the voltage above 4.5 volts?

Yes
1. Go to 6).
No
1. Go to 3).
3) (F856) 5 VOLT SUPPLY CIRCUIT SHORTED TO GROUND

Fig 2: Measuring The Resistance Between Ground And The 5 Volt Supply Circuit In The EGR Valve Assembly Harness Connector
Courtesy of CHRYSLER LLC

Turn the ignition on.

Disconnect the Powertrain Control Module (PCM) connector.

Measure the resistance between ground and the (F856) 5 Volt Supply circuit in the EGR Valve Assembly harness connector.

Is the resistance above 100 ohms?

Yes
1. Go to 4).
No
1. Repair the (F856) 5 Volt Supply circuit for a short to ground.
2. Perform PCM VERIFICATION TEST .
4) (F856) 5 VOLT SUPPLY CIRCUIT SHORTED TO (K900) SENSOR GROUND CIRCUIT

Fig 3: Measuring The Resistance Between The 5 Volt Supply Circuit And The Sensor Ground Circuit In The EGR Valve Assembly Harness Connector
Courtesy of CHRYSLER LLC

Measure the resistance between the (F856) 5 Volt Supply circuit and the (K900) Sensor Ground circuit in the EGR Valve Assembly harness connector.

Is the resistance above 100 ohms?

Yes
1. Go to 5).
No
1. Repair the (F856) 5 Volt Supply circuit for a short to the (K900) Sensor Ground circuit.
2. Perform PCM VERIFICATION TEST .
5) (F856) 5 VOLT SUPPLY CIRCUIT OPEN OR HIGH RESISTANCE

Fig 4: Measure The Resistance Between The (F856) 5 Volt Supply Circuit And The (K900) Sensor Ground Circuit In The EGR Valve Assembly Harness Connector.
Courtesy of CHRYSLER LLC

CAUTION: 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 (F856) 5 Volt Supply circuit between the EGR Valve Assembly harness connector and the appropriate terminal of special tool #8815.

Is the resistance below 5.0 ohms?

Yes
1. Go to 10).
No
1. Repair the (F856) 5 Volt Supply circuit for an open circuit or high resistance.
2. Perform PCM VERIFICATION TEST .
6) (K34) EGR SIGNAL CIRCUIT SHORTED TO GROUND

Fig 5: Measuring The Resistance Between Ground And The EGR Signal Circuit In The EGR Valve Assembly Harness Connector
Courtesy of CHRYSLER LLC

Turn the ignition off.

Disconnect the Powertrain Control Module (PCM) connector.

Measure the resistance between ground and the (K34) EGR Signal circuit in the EGR Valve Assembly harness connector.

Is the resistance above 100 ohms?

Yes
1. Go to 7).
No
1. Repair the (K34) EGR Signal circuit for a short to ground.
2. Perform PCM VERIFICATION TEST .
7) (K34) EGR SIGNAL CIRCUIT SHORTED TO (K900) SENSOR GROUND CIRCUIT

Fig 6: Measuring The Resistance Between The EGR Signal Circuit And The Sensor Ground Circuit In The EGR Valve Assembly Harness Connector
Courtesy of CHRYSLER LLC

Measure the resistance between the (K34) EGR Signal circuit and the (K900) Sensor Ground circuit in the EGR Valve Assembly harness connector.

Is the resistance above 100 ohms?

Yes
1. Go to 8).
No
1. Repair the (K34) EGR Signal circuit for a short to the (K900) Sensor Ground circuit.
2. Perform PCM VERIFICATION TEST .
8) (K34) EGR SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE

Fig 7: Measuring The Resistance Of The EGR Signal Circuit Between The EGR Valve Assembly Harness Connector And The Appropriate Terminal Of Special Tool #8815
Courtesy of CHRYSLER LLC

CAUTION: 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 (K34) EGR Signal circuit between the EGR Valve Assembly harness connector and the appropriate terminal of special tool #8815.

Is the resistance below 5.0 ohms?

Yes
1. Go to 9).
No
1. Repair the (K34) EGR Signal circuit for an open circuit or high resistance.
2. Perform PCM VERIFICATION TEST .
9) EGR VALVE ASSEMBLY
Turn the ignition off.

Connect the Powertrain Control Module (PCM) connector.

Turn the ignition on.

With the scan tool, read the EGR Valve Assembly signal voltage.

NOTE: The sensor voltage should be approximately 5.0 volts (plus or minus.1 volt) with the connector disconnected.

Does the scan tool display the voltage as described above?

Yes
1. Replace the EGR Valve Assembly in accordance with the Service Information.
2. Perform PCM VERIFICATION TEST .
No
1. Go to 10).
10) POWERTRAIN CONTROL MODULE (PCM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the EGR Valve Assembly and the Powertrain Control Module (PCM).

Look for any chafed, pierced, pinched, or partially broken wires.

Look for broken, bent, pushed out or corroded terminals.

Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.

Look for the data to change or for the DTC to reset during the wiggle test.

Refer to any Technical Service Bulletins that may apply.

Were any problems found?

Yes
1. Repair as necessary.
2. Perform PCM VERIFICATION TEST .
No
1. Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information.
2. Perform PCM VERIFICATION TEST .