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P0206 and U1016 Diagnostic for 2006 Cadillac SRX: Injector Fault and Engine Misfire

Model: Cadillac SRX Fault Code: U1016 Posted: 2019-07-13 21:58

My 2006 Cadillac SRX has developed a check engine light today. The onboard diagnostic system returned multiple codes: P0206, P0306, U1016, and C0561. Initially, I swapped the injector for cylinder 6 with another cylinder's injector, which temporarily cleared the codes and turned off the warning light. However, after two short drives, the check engine light reappeared along with new fault codes including P0206, P0300, P0306, U1016, and C0561. I'm seeking help to understand what could be causing this issue. The presence of both a P0206 (injector control fault for cylinder 6) and a P0306 (cylinder 6 misfire) suggests that the injector or its associated circuit may be faulty. Additionally, U1016 indicates an issue with the engine's fuel system control module, possibly related to communication between the powertrain control module (PCM) and the fuel injectors. I suspect a failing injector, damaged wiring, or a short in the injector driver circuit within the PCM. A proper diagnostic scan tool is required to confirm these codes and perform further analysis. What are the most likely causes of this combination of faults in a 2006 Cadillac SRX? Can a simple resistance test on the injector help identify the problem?

Related fault codes
U1016
Comments (5)
Anonymous 2019-07-14 08:40

Do you have access to a scan tool or just an OBD-II reader? It's important to use a proper diagnostic tool that can communicate with the vehicle's ECU. Clear all codes and then drive under normal conditions to see if they return. The P0206 code indicates a fault in the injector control circuit for cylinder 6, which could lead to a misfire detected by the P0306 code. This suggests a problem with either the injector itself or its wiring. A faulty injector may also cause an internal short that affects the PCM's driver circuit—this is especially concerning given the U1016 code (fuel system control module communication failure). To diagnose, perform a resistance test on the cylinder 6 injector and compare it to other injectors. If resistance values are outside normal ranges or inconsistent, that points to a failing component. Wiring connections should also be inspected for corrosion or damage.

Anonymous 2019-07-14 08:44

What specific part did you swap? Was it the coil pack or the injector? The fact that the P0306 code persisted after swapping the injector suggests that the issue is not with the coil. Since both P0206 and P0306 point to cylinder 6, the root cause likely lies in the fuel injection system for that cylinder—either a defective injector or an electrical fault in its control circuit. This misfire could be directly linked to the P0300 (random/multiple cylinder misfire) code as well.

Anonymous 2019-07-14 08:50

Is your vehicle equipped with a 3.6L or 4.6L engine? The fuel system and injector configuration may vary between these engines, which could affect how the P0206 and U1016 codes are interpreted.

Anonymous 2019-07-14 09:02

A common cause of this issue is an open circuit in the injector coil winding. A simple resistance test using a digital multimeter (DVM) can help identify whether the injector is functioning properly. Compare the measured resistance to the manufacturer's specifications for cylinder 6 injectors. If readings are significantly higher or lower than expected, it indicates a faulty injector that may be causing both misfire and communication errors in the fuel system.

Anonymous 2019-07-15 18:37

I understand frustration when users don't provide full details or respond to questions. However, clear, detailed input helps build accurate diagnostics. For this issue, a systematic approach—using proper tools and following diagnostic procedures—is essential for reliable results.