Encountering a situation where your scan tool refuses to communicate with your 2014 Sprinter can be a frustrating roadblock in diagnosing vehicle issues. This lack of communication prevents you from accessing crucial diagnostic trouble codes (DTCs) and live data, hindering your ability to pinpoint problems effectively. As a professional auto technician at vcdstool.com, I understand the importance of a reliable diagnostic process. This guide will walk you through a systematic approach to troubleshoot why your scan tool is failing to communicate with your 2014 Sprinter, ensuring you can get back to diagnosing and repairing efficiently.
Understanding the Communication Breakdown
Modern vehicles like the 2014 Sprinter rely on a complex network of computers, or modules, to control various systems. These modules communicate with each other via communication networks, often CAN (Controller Area Network) buses. The Engine Control Module (ECM) or Powertrain Control Module (PCM) is a critical component within this network, responsible for engine management and performance. When your scan tool fails to communicate with the ECM/PCM, it indicates a potential disruption in this communication pathway.
This diagnostic procedure focuses on addressing the “LOST COMMUNICATION WITH ECM/PCM” scenario, often indicated by a DTC related to this issue. Let’s delve into the troubleshooting steps.
Step-by-Step Diagnostic Procedure
Before you begin, ensure you have the correct diagnostic scan tool for your 2014 Sprinter. Verify that your scan tool is updated with the latest software and vehicle information. Also, confirm that the ignition is switched ON, the battery voltage is within the 10-16 volt range, and the Input/Output Diagnostic (IOD) fuse is properly installed.
Step 1: Verify Active DTC Presence
The first step is to confirm if the “Lost Communication” DTC is currently active.
- Connect your scan tool to the diagnostic port of your 2014 Sprinter.
- Power on the scan tool and navigate to the DTC reading section.
- Read active DTCs.
Is the “Lost Communication with ECM/PCM” DTC active?
- Yes: Proceed to Step 2.
- No: If the DTC is not active but was stored, refer to the “Stored Lost Communication” test procedure in your service manual. Consider performing a Body Verification Test using your scan tool to ensure the Body Control Module (BCM) is functioning correctly. This step helps rule out any intermittent issues or configuration problems.
Step 2: Check for Related Active DTCs
Communication issues can sometimes be triggered by other underlying problems. It’s crucial to check for any other active DTCs that might be related to the communication failure.
- Using your scan tool, read all active DTCs from all modules in the vehicle, not just the ECM/PCM.
Note: Pay close attention to DTCs related to:
- BCM Configuration: Incorrect BCM configuration can disrupt network communication.
- CAN Bus Hardware (Electrical): Shorts or open circuits in the CAN B or CAN C bus can prevent communication.
- VIN Missing/Mismatch: A missing or mismatched Vehicle Identification Number (VIN) can cause communication problems between modules.
- Battery or Ignition System: Low battery voltage or ignition system faults can affect module power and communication.
Does the scan tool display any active DTCs related to these conditions?
- Yes: Diagnose and repair these related DTCs first. Refer to your service manual for specific diagnostic procedures for each DTC. After addressing these related issues, perform the Body Verification Test again to clear codes and re-evaluate the communication problem.
- No: If there are no other related DTCs, proceed to Step 3.
Step 3: Verify ECM/PCM Activity on the Bus
This step checks if the ECM/PCM is even present and responding on the communication network.
- Turn the ignition ON.
- With the scan tool, navigate to “Network Diagnostics” or a similar function that allows you to view module status on the network.
- Verify if the ECM/PCM is listed as “active” or “present” on the bus. The scan tool should display a list of modules it detects on the network.
Is the ECM/PCM active on the bus?
- Yes: If the ECM/PCM is active on the bus, it suggests the module is powered and communicating to some extent. Proceed to Step 4.
- No: If the ECM/PCM is not active, it indicates a more serious issue. Refer to your service manual for “No Response from ECM or PCM” diagnostic procedures. This typically involves checking power and ground supply to the ECM/PCM, as well as CAN bus wiring integrity directly at the ECM/PCM connectors. Perform the Body Verification Test after any repairs.
Step 4: Check for Additional Communication Related DTCs
This final step helps determine if the communication issue is isolated to the ECM/PCM or if other modules are also experiencing communication problems with the ECM/PCM.
- With the scan tool, select “Network Diagnostics” again.
- Check if there is more than one module with active DTCs “Logged Against” the ECM/PCM. This means other modules are reporting communication faults specifically related to the ECM/PCM.
Are there multiple modules with active DTCs logged against the ECM/PCM?
- Yes: This scenario often points to a faulty ECM/PCM. In this case, replacement or reprogramming of the ECM/PCM may be necessary. Follow the service information for ECM/PCM replacement or update procedures. After replacement, perform the ECM Verification Test or Powertrain Verification Test as outlined in your service manual.
- No: If only the BCM (or the module you are initially communicating with) is reporting a lost communication DTC with the ECM/PCM, the issue might be localized to the module that set the DTC or the wiring between that module and the ECM/PCM. In this case, replacing or updating the module that set the DTC might be the solution, after thoroughly checking wiring and connections. Always refer to service information for module replacement/update procedures and perform the Body Verification Test afterward.
Conclusion
Troubleshooting a “2014 Sprinter Will Not Communicate With Scan Tool” issue requires a methodical approach. By following these steps, you can systematically narrow down the potential causes, from simple wiring problems to module malfunctions. Remember to always consult your 2014 Sprinter service manual for detailed wiring diagrams, connector pinouts, and specific diagnostic procedures. Accurate diagnosis is key to efficient repair and ensuring your customer’s Sprinter is back on the road quickly.
