Diagnostic Test

DTC IS ACTIVE
1. Turn the ignition on.
2. 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 may result in possible serious or fatal injury.
3. With the scan tool, select View DTCs.
  Is the status Active for this DTC?
  
  Yes
  - Go to step 2
  No
  - Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure
(F856) 5-VOLT SUPPLY CIRCUIT VOLTAGE

Fig 1: Checking 5-Volt Supply Circuit
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the MAP Sensor connector.
3. Turn the ignition on.
4. Measure the voltage of the (F856) 5-Volt Supply circuit in the MAP Sensor harness connector.
  Is the voltage between 4.5 and 5.5 volts?
  
  Yes
  - Go to step 3
  No
  - Go to step 7
(K1) MAP SIGNAL CIRCUIT VOLTAGE

Fig 2: Checking MAP Signal Circuit
Courtesy of CHRYSLER LLC
1. Measure the voltage of the (K1) MAP Signal circuit in the MAP Sensor harness connector.
  Is the voltage between 4.5 and 5.5 volts?
  
  Yes
  - Go to step 4
  No
  - Go to step 11
(K900) SENSOR GROUND CIRCUIT TEST

Fig 3: Checking Ground Circuit
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Using a 12 volt test light connected to 12 volts, check the (K900) Sensor Ground in the MAP Sensor harness connector.
  NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
  
  Is the test light illuminated and bright?
  
  Yes
  - Go to step 5
  No
  - Go to step 15
(F856) 5-VOLT SUPPLY CIRCUIT SHORTED TO THE (K1) MAP SIGNAL CIRCUIT

Fig 4: Checking 5-Volt Supply Circuit
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the Powertrain Control Module (PCM) connector.
3. Measure the resistance between the (F856) 5-Volt Supply circuit and the (K1) MAP Signal circuit in the MAP Sensor harness connector.
  Is the resistance above 100 ohms?
  
  Yes
  - Go to step 6
  No
  - Repair the (F856) 5-Volt Supply circuit for a short to the (K1) MAP Signal circuit.
  - Perform the PCM Verification Test. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
MAP SENSOR
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the MAP Sensor and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Inspect the MAP Sensor for any condition that would result in an incorrect signal, such as damage or contamination.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the PCM Verification Test. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Replace the MAP Sensor.
  - Perform the PCM Verification Test. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
(F856) 5-VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE

Fig 5: Checking 5-Volt Supply Circuit
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the Powertrain Control Module (PCM) connector.
3. Turn the ignition on.
4. Measure the voltage of the (F856) 5-Volt Supply circuit in the MAP Sensor harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the (F856) 5-Volt Supply circuit for a short to voltage.
  - Perform the PCM Verification Test. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 8
(F856) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND

Fig 6: Checking 5-Volt Supply Circuit
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Measure the resistance between ground and the (F856) 5-Volt Supply circuit in the MAP Sensor harness connector.
  Is the resistance above 100 ohms?
  
  Yes
  - Go to step 9
  No
  - Repair the (F856) 5-Volt Supply circuit for a short to ground.
  - Perform the PCM Verification Test. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
(F856) 5-VOLT SUPPLY CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT

Fig 7: Checking 5-Volt Supply Circuit
Courtesy of CHRYSLER LLC
1. Measure the resistance between the (F856) 5-Volt Supply circuit and the (K900) Sensor Ground circuit in the MAP Sensor harness connector.
  Is the resistance above 100 ohms?
  
  Yes
  - Go to step 10
  No
  - Repair the (F856) 5-Volt Supply circuit for a short to the (K900) Sensor Ground circuit.
  - Perform the PCM Verification Test. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
(F856) 5-VOLT SUPPLY CIRCUIT OPEN OR HIGH RESISTANCE

Fig 8: Checking 5-Volt Supply Circuit
Courtesy of CHRYSLER LLC

NOTE: When checking circuits at the Powertrain Control Module (PCM), be careful not to damage or distort the connector terminals. Improper measurement technique could result in poor pin to terminal contact.
1. Measure the resistance of the (F856) 5-Volt Supply circuit between the MAP Sensor harness connector and the Powertrain Control Module (PCM) harness connector.
  Is the resistance below 5.0 ohms?
  
  Yes
  - Go to step 16
  No
  - Repair the (F856) 5-Volt Supply circuit for an open circuit or high resistance.
  - Perform the PCM Verification Test. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
(K1) MAP SIGNAL CIRCUIT SHORTED TO VOLTAGE

Fig 9: Checking MAP Signal Circuit
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the Powertrain Control Module (PCM) connector.
3. Turn the ignition on.
4. Measure the voltage of the (K1) MAP Signal circuit in the MAP Sensor harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the (K1) MAP Signal circuit for a short to voltage.
  - Perform the PCM Verification Test. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 12
(K1) MAP SIGNAL CIRCUIT SHORTED TO GROUND

Fig 10: Checking MAP Signal Circuit
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Measure the resistance between ground and the (K1) MAP Signal circuit in the MAP Sensor harness connector.
  Is the resistance above 100 ohms?
  
  Yes
  - Go to step 13
  No
  - Repair the (K1) MAP Signal circuit for a short to ground.
  - Perform the PCM Verification Test. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
(K1) MAP SIGNAL CIRCUIT SHORTED TO (K900) SENSOR GROUND CIRCUIT

Fig 11: Checking MAP Signal Circuit
Courtesy of CHRYSLER LLC
1. Measure the resistance between the (K1) MAP Signal circuit and the (K900) Sensor Ground circuit in the MAP Sensor harness connector.
  Is the resistance above 100 ohms?
  
  Yes
  - Go to step 14
  No
  - Repair the (K1) MAP Signal circuit for a short to the (K900) Sensor Ground circuit.
  - Perform the PCM Verification Test. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
(K1) MAP SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE

Fig 12: Checking MAP Signal Circuit
Courtesy of CHRYSLER LLC

NOTE: When checking circuits at the Powertrain Control Module (PCM), be careful not to damage or distort the connector terminals. Improper measurement technique could result in poor pin to terminal contact.
1. Measure the resistance of the (K1) MAP Signal circuit between the MAP Sensor harness connector and the Powertrain Control Module (PCM) harness connector.
  Is the resistance below 5.0 ohms?
  
  Yes
  - Go to step 16
  No
  - Repair the (K1) MAP Signal circuit for an open circuit or high resistance.
  - Perform the PCM Verification Test. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
(K900) SENSOR GROUND CIRCUIT OPEN OR HIGH RESISTANCE

Fig 13: Checking MAP Sensor Ground Circuit
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the Powertrain Control Module (PCM) connector.
  NOTE: When checking circuits at the Powertrain Control Module (PCM), be careful not to damage or distort the connector terminals. Improper measurement technique could result in poor pin to terminal contact.
3. Measure the resistance of the (K900) Sensor Ground circuit between the MAP Sensor harness connector and the Powertrain Control Module (PCM) harness connector.
  Is the resistance below 5.0 ohms?
  
  Yes
  - Go to step 16
  No
  - Repair the circuit for an open circuit or high resistance.
  - Perform the PCM Verification Test. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the MAP Sensor and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
5. Look for the data to change or for the DTC to reset during the wiggle test.
6. Refer to any Technical Service Bulletins that may apply.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the PCM Verification Test. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information.
  - Perform the PCM Verification Test. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .