**I AM POSTING THIS IN A FEW SUBS TRYING TO GET HELP**
Working on a 2012 Toyota Highlander FWD, 2.7L 1AR-FE. There's a possibility the engine/transmission came from a Toyota Venza with the same 2.7L engine, but we don't know the donor year.
**Current trouble codes:**
- **P0011** – Intake camshaft timing overadvanced (Bank 1)
- **P0015** – Exhaust camshaft timing overretarded (Bank 1)
Both codes return after clearing.
**Symptoms:**
- Starts and idles fairly smoothly when cold, around 1,000 RPM.
- Once warmed up, idle drops to roughly 500–750 RPM and becomes noticeably rough.
- Before the timing-chain replacement, the engine ran fine other than a brief rattle on startup.
- When we started the timing-chain job using a replacement timing kit, we discovered that the original timing-chain guides had deteriorated and were falling apart.
**What's been replaced or checked:**
- Timing chain replaced using a timing-chain kit.
- Both intake and exhaust VVT oil-control solenoids replaced with new units.
- Spark plugs replaced.
- Crankshaft position sensor replaced.
- Found and repaired a broken ground strap running from the body to the engine mount. Repair made no noticeable difference.
- Checked EFI MAIN, EFI NO.1, EFI NO.2, EFI NO.3 and IG2 fuses; all good.
- Visually inspected vacuum hoses.
- Removed timing cover and verified all three colored timing-chain links align with the factory timing marks on both camshaft sprockets and crankshaft.
- Neither cam phaser was removed or had its center bolt loosened during the timing-chain work.
- Tested starting and idling with each VVT solenoid unplugged separately. **Neither the intake nor exhaust solenoid being unplugged made any noticeable difference in cold starting or cold idle.** The ECM detected the disconnected circuits as expected. These tests were performed while the engine was cold, so we haven't established whether unplugging either affects the rough idle when warm.
**TOPDON TopScan live data (engine running):**
- VVT Control Status #1: OFF
- VVT Aim Angle #1: 0%
- VVT OCV Duty #1: 0%
- VVT Change Angle #1: 0°
- VVT Ex OCV Duty #1: 0%
- VVT Ex Chg Angle #1: 0°
- VVT Advance Fail: ON
These readings remained unchanged when RPM was raised to approximately 1,500–2,000 with no load. Not sure whether the ECM is inhibiting VVT operation or whether the scan tool isn't reporting the data correctly.
**Something interesting we noticed:**
While manually rotating the crankshaft with a ratchet (timing chain installed and tensioned, spark plugs installed), the intake phaser's outer sprocket continued moving smoothly with the chain, but the inner portion, center bolt and camshaft appeared to suddenly jump relative to the sprocket, then return to the parked position.
This makes us suspicious of the intake phaser's internal locking mechanism, although we haven't confirmed it's defective.
**Next steps:**
I already have a replacement **intake VVT phaser on the way**. We're also planning to perform a mechanical oil-pressure test tomorrow, **October 19**, checking pressure at hot idle and higher RPM.
**Google Drive link with photos/videos of the engine, timing components and phaser movement:**
[View Google Drive folder – Photos and videos](https://drive.google.com/drive/folders/1X9BNtLIRxINAus7hjcxdwKOq9H1Tl66Q?usp=drive_link)
**Questions:**
1. Does the intake phaser's internal movement during manual crankshaft rotation suggest a failed or disengaged locking pin, or can that be normal?
2. Could one defective intake phaser contribute to both P0011 and P0015, or should we suspect a shared oil-pressure/oil-delivery issue?
3. If mechanical oil pressure tests normal, what would you investigate next?
Trying to avoid throwing more parts at it unnecessarily. Any insight from someone familiar with Toyota's 1AR-FE VVT system would be greatly appreciated.
Working on a 2012 Toyota Highlander FWD, 2.7L 1AR-FE. There's a possibility the engine/transmission came from a Toyota Venza with the same 2.7L engine, but we don't know the donor year.
**Current trouble codes:**
- **P0011** – Intake camshaft timing overadvanced (Bank 1)
- **P0015** – Exhaust camshaft timing overretarded (Bank 1)
Both codes return after clearing.
**Symptoms:**
- Starts and idles fairly smoothly when cold, around 1,000 RPM.
- Once warmed up, idle drops to roughly 500–750 RPM and becomes noticeably rough.
- Before the timing-chain replacement, the engine ran fine other than a brief rattle on startup.
- When we started the timing-chain job using a replacement timing kit, we discovered that the original timing-chain guides had deteriorated and were falling apart.
**What's been replaced or checked:**
- Timing chain replaced using a timing-chain kit.
- Both intake and exhaust VVT oil-control solenoids replaced with new units.
- Spark plugs replaced.
- Crankshaft position sensor replaced.
- Found and repaired a broken ground strap running from the body to the engine mount. Repair made no noticeable difference.
- Checked EFI MAIN, EFI NO.1, EFI NO.2, EFI NO.3 and IG2 fuses; all good.
- Visually inspected vacuum hoses.
- Removed timing cover and verified all three colored timing-chain links align with the factory timing marks on both camshaft sprockets and crankshaft.
- Neither cam phaser was removed or had its center bolt loosened during the timing-chain work.
- Tested starting and idling with each VVT solenoid unplugged separately. **Neither the intake nor exhaust solenoid being unplugged made any noticeable difference in cold starting or cold idle.** The ECM detected the disconnected circuits as expected. These tests were performed while the engine was cold, so we haven't established whether unplugging either affects the rough idle when warm.
**TOPDON TopScan live data (engine running):**
- VVT Control Status #1: OFF
- VVT Aim Angle #1: 0%
- VVT OCV Duty #1: 0%
- VVT Change Angle #1: 0°
- VVT Ex OCV Duty #1: 0%
- VVT Ex Chg Angle #1: 0°
- VVT Advance Fail: ON
These readings remained unchanged when RPM was raised to approximately 1,500–2,000 with no load. Not sure whether the ECM is inhibiting VVT operation or whether the scan tool isn't reporting the data correctly.
**Something interesting we noticed:**
While manually rotating the crankshaft with a ratchet (timing chain installed and tensioned, spark plugs installed), the intake phaser's outer sprocket continued moving smoothly with the chain, but the inner portion, center bolt and camshaft appeared to suddenly jump relative to the sprocket, then return to the parked position.
This makes us suspicious of the intake phaser's internal locking mechanism, although we haven't confirmed it's defective.
**Next steps:**
I already have a replacement **intake VVT phaser on the way**. We're also planning to perform a mechanical oil-pressure test tomorrow, **October 19**, checking pressure at hot idle and higher RPM.
**Google Drive link with photos/videos of the engine, timing components and phaser movement:**
[View Google Drive folder – Photos and videos](https://drive.google.com/drive/folders/1X9BNtLIRxINAus7hjcxdwKOq9H1Tl66Q?usp=drive_link)
**Questions:**
1. Does the intake phaser's internal movement during manual crankshaft rotation suggest a failed or disengaged locking pin, or can that be normal?
2. Could one defective intake phaser contribute to both P0011 and P0015, or should we suspect a shared oil-pressure/oil-delivery issue?
3. If mechanical oil pressure tests normal, what would you investigate next?
Trying to avoid throwing more parts at it unnecessarily. Any insight from someone familiar with Toyota's 1AR-FE VVT system would be greatly appreciated.
Oct 18, 2026 at 8:19 PM