Variable Cam Timing Overretarded (Bank #2)
The engine's camshaft timing on Bank 2 is stuck too far retarded (delayed), like an orchestra where one section is playing behind the beat. The ECU can't advance the timing enough to meet performance targets.
The ECU monitors camshaft position relative to crankshaft position using the CMP sensor on Bank 2. It commands the variable cam timing solenoid to advance or retard the cam. When actual cam timing lags behind commanded timing beyond a calibrated threshold for too long, the fault sets.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Cam Timing Advance (Bank 2) | Within 5° of commanded position | Retarded >10° or cannot advance for 2+ sec |
| VCT Solenoid Response | Solenoid energizes and timing shifts within 500ms | No timing response or sluggish response detected |
Code P1393 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, P1393 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.