SPN 1590 FMI 9 – Adaptive Cruise Control Message Not Received Fault Code (Symptoms, Causes & Fix)
The SPN 1590 FMI 9 fault code indicates that the Adaptive Cruise Control (ACC) system is not receiving the necessary messages from the radar sensor. This diesel engine fault code suggests a communication breakdown between the radar sensor and the Electronic Control Module (ECM), which can affect the functionality of the ACC system.
What SPN 1590 FMI 9 Means
The SPN 1590 FMI 9 fault code is triggered when the ECM fails to receive expected data from the radar sensor used in the Adaptive Cruise Control system. This diagnostic trouble code highlights a potential issue in the communication path, which could be due to electrical faults or sensor misalignment.
Common Causes of This Fault Code
- Faulty or misaligned radar sensor
- Damaged or corroded wiring harness
- Faulty ACC module
- CAN communication issues
- Connector corrosion
Symptoms Drivers May Notice
When the SPN 1590 FMI 9 fault code is active, drivers may notice that the Adaptive Cruise Control system is not functioning properly. This could manifest as the cruise control not engaging, or the system deactivating unexpectedly. Additionally, a warning light may illuminate on the dashboard.
How Technicians Diagnose This Fault
Technicians begin diagnosing the SPN 1590 FMI 9 fault code by performing a visual inspection of the radar sensor for any signs of physical damage or misalignment. Next, they check the wiring harness for continuity, damage, or corrosion. Using a multimeter, they verify the power and ground connections to the ACC module. A CAN network integrity test is also conducted to ensure proper communication between the sensor and the ECM. Diagnostic software may be used to verify data signals and ensure the ECM is receiving accurate information.
Common Misdiagnosis
Common misdiagnoses include replacing the radar sensor without checking its alignment, assuming a faulty ACC module without verifying power and ground connections, and overlooking wiring issues due to intermittent faults. These mistakes can lead to unnecessary part replacements and prolonged troubleshooting.
Can You Keep Driving?
While the truck can generally continue operating with the SPN 1590 FMI 9 fault code active, the Adaptive Cruise Control system will not function correctly. This may not immediately affect the drivability of the truck, but it is advisable to address the issue promptly to restore full system functionality and ensure safety.
Mechanic's Diagnostic Tip
Before replacing any components, ensure that the radar sensor is properly aligned and free of obstructions. Misalignment is a frequent cause of communication issues and can often be corrected without part replacement.
Frequently Asked Questions
Q: What tools are needed to diagnose SPN 1590 FMI 9?
A: A multimeter, diagnostic software, and potentially a CAN network tester are essential for diagnosing this fault code.
Q: Can a faulty radar sensor cause other issues?
A: Yes, a faulty radar sensor can affect the entire ACC system, leading to cruise control malfunctions.
Q: Is it necessary to recalibrate the radar sensor after alignment?
A: Yes, recalibration may be necessary to ensure the sensor is accurately detecting objects and communicating with the ECM.
