Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC P1259: Variable Valve Timing & Lift Electronic Control System Malfunction
2004 Acura 3.5RLSECTION DTC P1259: Variable Valve Timing & Lift Electronic Control System Malfunction
WARNING: This page is about a different car, the 2003 Acura RSX. However, it is still accessible from the selected car via links, so may be relevant.
- Perform ECM/PCM reset procedure. See ECM/PCM RESET PROCEDURE/CLEARING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM. Check engine oil level and top off if necessary. Check for external damage to oil pan (K20A3 engine). Start engine and run at 3000 RPM, with no load (in park or neutral), until radiator fan comes on. Road test vehicle. Accelerate in 1st gear to more than 4000 RPM and hold for at least 2 seconds. If DTC P1259 does not reset during first road test, repeat road test 2 more times. If DTC P1259 resets, go to next step. If DTC P1259 does not reset, problem is intermittent. System is functioning properly at this time. Check for poor connection(s) or loose wire(s) between Variable Valve Timing & Lift Electronic Control (VTEC) solenoid valve 2-pin harness connector and ECM/PCM 24-pin "B" harness connector. See Figure . See appropriate wiring diagram under ENGINE PERFORMANCE in WIRING DIAGRAMS. Repair as necessary.
- Turn ignition switch off. Disconnect VTEC oil pressure switch 2-pin harness connector. Check for continuity between VTEC oil pressure switch 2-pin connector terminals. If continuity is present, go to next step. If continuity is not present, replace VTEC oil pressure switch.
- Turn ignition switch on. Measure voltage between ground and VTEC oil pressure switch 2-pin harness connector terminal No. 1 (Blue/Black wire). If battery voltage is present, go to step 6 . If battery voltage is not present, go to next step.
- Measure voltage between ground and ECM/PCM 24-pin "B" harness connector terminal No. 9 (Blue/Black wire). If battery voltage is not present, go to next step. If battery voltage is present, repair open in Blue/Black wire between ECM/PCM 24-pin "B" harness connector terminal No. 9 and VTEC oil pressure switch 2-pin harness connector terminal No. 1.
- Turn ignition switch off. Disconnect ECM/PCM 24-pin "B" harness connector. Check for continuity between ground and ECM/PCM 24-pin "B" harness connector terminal No. 9 (Blue/Black wire). If continuity is present, repair short in Blue/Black wire between ECM/PCM 24-pin "B" harness connector and VTEC oil pressure switch 2-pin harness connector terminal No. 1. If continuity is not present, update ECM/PCM or substitute with known-good ECM/PCM. If symptom or indication goes away, replace original ECM/PCM.
- Measure voltage between VTEC oil pressure switch 2-pin harness connector terminals. If battery voltage is present, go to next step. If battery voltage is not present, repair open in Brown/Yellow wire between VTEC pressure switch 2-pin harness connector terminal No. 2 and ground terminal G101.
- Turn ignition switch off. Disconnect VTEC solenoid valve 2-pin harness connector. Check resistance between VTEC solenoid valve 2-pin connector terminals. If resistance reading is 14-30 ohms, go to next step. If resistance reading is not as specified, replace VTEC solenoid valve. See VTC OIL CONTROL SOLENOID VALVE (RSX) under VARIABLE VALVE TIMING & LIFT ELECTRONIC CONTROL SYSTEM in REMOVAL & INSTALLATION article.
CAUTION:
Keep measuring time as short as possible (less than one minute) because of engine running with no load.
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.