P1259 ISUZU Possible Causes
- Low engine oil level or oil pressure
- Faulty Variable Valve Timing and Lift Electronic Control (VTEC) solenoid
- VTEC solenoid wiring harness is open or short-circuited
- Poor electrical connection in the VTEC circuit
- Faulty VTEC oil pressure switch
How is the P1259 ISUZU code repaired?
Start by checking the “Possible Causes” listed above. Visually inspect the wiring harness and related connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.
When is the code detected?
P1259 is set when there is a problem in the VTEC oil pressure switch circuit or the VTEC solenoid circuit
Possible Symptoms
- Check engine light on (or engine maintenance warning light)
P1259 ISUZU Meaning
The Variable Valve Timing and Lift Electronic Control (VTEC) system activates the VTEC solenoid through the Powertrain Control Module (PCM) command, and it loads/unloads the hydraulic circuit of the VTEC mechanism that is installed in the valve system to switch valve timing between Low and High. The PCM monitors the oil pressure conditions in the hydraulic circuit of the VTEC mechanism based on the VTEC oil pressure switch downstream of the VTEC solenoid. If there is a disparity between the oil pressure condition in the hydraulic circuit that is determined by the PCM command, and the oil pressure condition that is determined by the state of the VTEC oil pressure switch, the system is considered faulty and the P1259 code is stored.