Diagnostic Test

WARNING: This page is about a different car, the 2024 Jeep Grand Cherokee L. However, it is still accessible from the selected car via links, so may be relevant.

READ AND RECORD DTCS AND ENVIRONMENTAL DATA - ERASE DTCS AND CHECK FOR THE DTC TO RETURN
1. With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
2. For future reference, with the scan tool, run and save a vehicle Scan Report and all related recorded data.
3. With the scan tool, erase all DTCs.
4. Turn the ignition off for a minimum of 10.0 seconds.
5. Turn the ignition on.
6. Using the When Monitored and Set Conditions above and recorded data, operate the vehicle in the conditions that set the DTC.
7. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK FOR OTHER DTCS
1. Refer to the recorded DTCs.
  Are there any Engine Misfire DTCs active or pending?
  
  Yes
  - Perform the applicable diagnostic procedure(s). Refer to DIAGNOSTIC CODE INDEX, 5.7L .
  No
  - Go To 3
CHECK THE MDS SOLENOID 1 CONNECTORS
1. Turn the ignition off.
2. Inspect the MDS Solenoid harness connectors, jumper connectors, and all male and female terminals for the following conditions:
  - Proper connector installation.
  - Damaged connector locks.
  - Corrosion.
  - Other signs of water intrusion.
  - Weather seal damage (if equipped).
  - Bent terminals.
  - Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  - Terminals that have been pushed back into the connector cavity.
  - Check for spread terminals and verify proper terminal tension.
  Were and problems found?
  
  Yes
  - Repair any conditions that are found.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
CHECK THE MDS SOLENOID 1 CONTROL CIRCUIT ON THE PCM SIDE OF THE IN-LINE HARNESS CONNECTOR FOR AN OPEN/HIGH RESISTANCE
NOTE:
The DTC must not be active for the actuator test to operate properly, clear all DTC before continuing.
1. Turn the ignition off.
2. Disconnect the in-line harness connector located behind the left side cylinder head.
3. Using a 12-volt test light, jump from the Ground circuit to the MDS Solenoid 1 (K451) Control circuit in the in-line harness connector (PCM side).
4. Turn the ignition on.
5. Using the scan tool, actuate the MDS Solenoid 1.
  Does the 12-volt test light flash on and off?
  
  Yes
  - Go To 5
  No
  - Go To 6
CHECK THE MDS SOLENOID RESISTANCE
1. Turn the ignition off.
2. Measure the resistance between the Ground circuit and the MDS Solenoid 1 (K451) Control circuit in the in-line harness connector (MDS side).
  NOTE:
  The normal resistance value will be between 8.0 and 25.0 Ohms based on temperature.
  
  What is the measured the resistance?
  
  Under 8.0 Ohms
  - Go To 15
  8.0 to 25.0 Ohms
  - Go To 14
  Over 25.0 Ohms
  - Go To 10
CHECK THE GROUND CIRCUIT ON THE PCM SIDE OF THE IN-LINE HARNESS CONNECTOR FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Using a 12-volt test light connected to the 12 Volts, probe the Ground circuit in the in-line harness connector (PCM side).
  Does the test light illuminate brightly?
  
  Yes
  - Go To 7
  No
  - Repair the open in the Ground circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE MDS SOLENOID 1 (K451) CONTROL CIRCUIT ON THE PCM SIDE OF THE IN-LINE HARNESS CONNECTOR FOR A SHORT TO BATTERY VOLTAGE
1. Disconnect the PCM C2 harness connector.
2. Turn the ignition on.
3. Measure the voltage on the MDS Solenoid 1 (K451) Control circuit in the in-line harness connector (PCM side).
  Does the Voltmeter indicate voltage present?
  
  Yes
  - Repair the short to battery voltage in the MDS Solenoid 1 (K451) Control circuit between the PCM C2 harness connector and in-line harness connector.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 8
CHECK THE MDS SOLENOID 1 (K451) CONTROL CIRCUIT ON THE PCM SIDE OF THE IN-LINE HARNESS CONNECTOR FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Measure the resistance between ground and the MDS Solenoid 1 (K451) Control circuit in the in-line harness connector (PCM side).
  Is the resistance below 100 Ohms?
  
  Yes
  - Repair the short to ground in the MDS Solenoid 1 (K451) Control circuit between the PCM harness connector and the in-line harness connector.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 9
CHECK THE MDS SOLENOID 1 (K451) CONTROL CIRCUIT ON THE PCM SIDE OF THE IN-LINE HARNESS CONNECTOR FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the MDS Solenoid 1 (K451) Control circuit from the in-line harness connector to the PCM C2 harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Replace and program the Powertrain Control Module in accordance with the service information. Refer to MODULE, POWERTRAIN CONTROL (PCM), REMOVAL AND INSTALLATION .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Repair the open in the MDS Solenoid 1 (K451) Control circuit between the in-line harness connector and the PCM C2 harness connector.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE GROUND CIRCUIT ON THE MDS SIDE OF THE IN-LINE HARNESS CONNECTOR FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Gain access to the MDS Solenoid. Refer to SOLENOID, MULTIPLE DISPLACEMENT, REMOVAL AND INSTALLATION, 5.7L .
3. Disconnect the MDS harness connector.
4. Measure the resistance of the Ground circuit between the in-line harness connector and the MDS 1 harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 11
  No
  - Repair the open in the Ground circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE MDS SOLENOID 1 (K451) CONTROL CIRCUIT ON THE MDS SIDE OF THE IN-LINE HARNESS CONNECTOR FOR A SHORT TO BATTERY VOLTAGE
1. Turn the ignition on.
2. Measure the voltage on the MDS Solenoid 1 (K451) Control circuit in the MDS Solenoid 1 harness connector.
  Does the Voltmeter indicate voltage present?
  
  Yes
  - Repair the short to battery voltage in the MDS Solenoid 1 (K451) Control circuit between the in-line harness connector and the MDS 1 harness connector.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 12
CHECK THE MDS SOLENOID 1 (K451) CONTROL CIRCUIT ON THE MDS SIDE OF THE IN-LINE HARNESS CONNECTOR FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Measure the resistance between ground and the MDS Solenoid 1 (K451) Control circuit in the MDS Solenoid 1 harness connector.
  Is the resistance below 10k Ohms?
  
  Yes
  - Repair the short to ground in the MDS Solenoid 1 (K451) Control circuit between the in-line harness connector and the MDS harness connector.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 13
CHECK THE MDS SOLENOID 1 (K451) CONTROL CIRCUIT ON THE MDS SIDE OF THE IN-LINE HARNESS CONNECTOR FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the MDS Solenoid 1 (K451) Control circuit from the MDS Solenoid 1 harness connector to the in-line harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Replace the MDS Solenoid in accordance with the Service Information. Refer to SOLENOID, MULTIPLE DISPLACEMENT, REMOVAL AND INSTALLATION, 5.7L .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Repair the open in the MDS Solenoid 1 (K451) Control circuit between the in-line harness connector and the MDS harness connector.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE IN-LINE HARNESS CONNECTOR AND GROUND CONNECTION FOR DAMAGE OR IMPROPER FIT
1. Inspect the in-line harness connector.
2. Make sure the Ground terminal and Control terminal are fastened securely into the connector and there are no signs of corrosion or damage.
3. Check wiring to terminal connection. Look for an internal broken wire under the insulation.
4. Inspect the Ground for a tight, clean connection.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
ISOLATE AND CHECK THE MDS SOLENOID 1 (K451) CONTROL CIRCUIT FOR A SHORT TO GROUND
1. The ignition must be off when checking a circuit for continuity to ground.
2. Isolate the circuit by disconnecting the Electronic Control Unit (ECU) and every component harness connector containing the circuit being tested. Note: Use the wiring diagram as a guide to follow the path of the circuit.
3. Connect the negative lead of the DVOM to a known good ground.
4. With the positive lead of the DVOM, probe the circuit being tested at the component harness connector and check for continuity between the circuit and ground.
  NOTE:
  There should be no continuity between ground and the circuit being tested.
  
  Is there continuity between ground and the circuit being tested?
  
  Yes
  - Repair the circuit for a short to ground. Use the wiring diagram as a guide to trace the circuit and look for any in-line connectors to help isolate the location of the short.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Replace the MDS Solenoid in accordance with the Service Information. Refer to SOLENOID, MULTIPLE DISPLACEMENT, REMOVAL AND INSTALLATION, 5.7L .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .