P1346 error code

Hi all. I have a 2004 Mk1 1.3 petrol Yaris (2SZ-FE). Error code P1346 has been logged: VVT sensor/camshaft position sensor circuit range/performance problem (bank 1). The engine appears to run fine - it pulls well and is smooth when driven or at idle with no rattling from the timing chain.

I took a chance and replaced the camshaft sensor but that didn’t resolve the problem.

I took the oil control valve out and cleaned it as well as its screen filter. Both were clean. I cleared the stored error code but it eventually came back.

I’ve checked the resistance of the oil control valve - it measured 0.5 ohms and very slowly went up as I held the multimeter probes in place. Is this normal? Or should the resistance measure 6.9 - 7.9 ohms straight away?

I tested the oil control valve by connecting it to a 9v Battery. The solenoid worked fine when I cycled the power from the Battery on and off.

With the ignition turned to accessory power, the electrical connector for the oil control valve measured 1.5v. Should the voltage be higher when the ignition is turned to accessory power?

I also disconnected the oil control valve from the engine but left it connected to the harness. I turned the ignition to accessory power but the oil control valve solenoid didn’t respond.

The oil control valve appears to be faulty. Is there a chance that its electrical connector is as well?

Any ideas are welcome. Thanks.

23 hours ago, orangejuice said:

Hi all. I have a 2004 Mk1 1.3 petrol Yaris (2SZ-FE). Error code P1346 has been logged: VVT sensor/camshaft position sensor circuit range/performance problem (bank 1). The engine appears to run fine - it pulls well and is smooth when driven or at idle with no rattling from the timing chain.

I took a chance and replaced the camshaft sensor but that didn’t resolve the problem.

I took the oil control valve out and cleaned it as well as its screen filter. Both were clean. I cleared the stored error code but it eventually came back.

I’ve checked the resistance of the oil control valve - it measured 0.5 ohms and very slowly went up as I held the multimeter probes in place. Is this normal? Or should the resistance measure 6.9 - 7.9 ohms straight away?

I tested the oil control valve by connecting it to a 9v battery. The solenoid worked fine when I cycled the power from the battery on and off.

With the ignition turned to accessory power, the electrical connector for the oil control valve measured 1.5v. Should the voltage be higher when the ignition is turned to accessory power?

I also disconnected the oil control valve from the engine but left it connected to the harness. I turned the ignition to accessory power but the oil control valve solenoid didn’t respond.

The oil control valve appears to be faulty. Is there a chance that its electrical connector is as well?

Any ideas are welcome. Thanks.

Hi, 

I'm currently fighting the exact same DTC code with the exact same engine and same trim. P1346. My car also runs well and idles fine. Had my timing chain done by a garage MOT before last but the code returned. I service my car regularly myself, full service including spark plugs and camshaft sensor. Changed the OCV which helped for about 5 miles. Still fighting the code 2 years later. 

Have you had any engine work done with your car at all? Do you service it regularly? 

0.5 ohms reading is odd as my new one read 7.9 ohms immediately at ambient temperature. It reads the same 7 months later. Are you sure you connected your multi-meter properly? 

As far as I'm aware, the OCV won't react like a typical sensor. It gets its signal directly from the ECM when needed. It won't activate at idle, only when it's needed to open for more oil or close for less. Unless I'm mistaken? 

Keen to see if you can get yours working as I've not had success yet

Pete

The ecu will not like that 0.5 - i would say put a fresh Battery in your meter and retest

@ShiftedReality1990

i would test the wiring end to end and check pin fitment, a intermittent code could be a worn vvti pulley

not sure if the mk1 can perform an active test on the solenoid (PWM control)

if it's a MIL code it will log freeze frame data for that code

31 minutes ago, flash22 said:

The ecu will not like that 0.5 - i would say put a fresh battery in your meter and retest

@ShiftedReality1990

i would test the wiring end to end and check pin fitment, a intermittent code could be a worn vvti pulley

not sure if the mk1 can perform an active test on the solenoid (PWM control)

if it's a MIL code it will log freeze frame data for that code

Don't want to take over the thread, but how do I test the wiring end to end? Am I looking for continuity between the wiring from the ocv plug to the ECM through the wiring loom? I have no idea what wire is what, I'm guessing follow the wires from the ocv plug to the main plug near the fuse box in the engine bay?  My ECU stored the DTC as my code reader finds it stored, but the same P1346 is also pending too. No other codes stored apart from this

Yes end to end continuity and resistance, 7.9 ohms is borderline high and that will rise with engine bay temps, because its a new part doesn't mean its good

I’ve managed to borrow another multimeter from another friend. I checked the reliability of the multimeter by measuring the resistance of some 300 ohm resistors. The multimeter measured correctly. I then checked the resistance of the oil control valve. It measured 7.9 ohms, then dropped and fluctuated between 7.5 ohms and 7.6 ohms. Then it dropped a bit again and fluctuated between 7.4 ohms and 7.5 ohms. Is the oil control valve faulty?

its in the upper end of the spec range, you will always get some variation due to temperature and the leads

I’ll check the grounds in the engine bay next, and then clean the electrical connector for the oil control valve with electrical cleaner. Are there any ground points in particular that I should check? Should I check with the Battery resting and with the engine on?

grounds shouldn't matter as it is wired directly to the ECU iirc

I had the idea of checking the grounds from this thread: 

Just to double check. What resistance should the camshaft sensor be?

you will need a scope or mid-high end scan tool to read the cam sensor

any chain noise at start up ? what grade oil are you running??

we are getting into ECU or worn cam chain/tensioner territory

freeze frame data for the code would help a lot

No chain nose at start-up. The resistance of the camshaft sensor is 2,300 ohms. Running 5w30 fully synthetic oil. Is the ECU a straight swap?

Edit: I’ll get the freeze frame data and get back to you.

The ECU will require programming to change the VIN, set the mileage and sync the immobiliser

i wouldn't go throwing parts at it, you need that freeze-frame data

you can use a techstream clone like a mini vci

I cleared the code earlier and went for a drive. I travelled about 66 miles in about 1 hour 15 minutes, and the light didn't come on. I parked up, switched off the engine, waited a few moments, and then switched the engine back on. The code came back after about 30 seconds whilst idling. Here's the freeze frame data when the code appeared whilst idling:

• Fuel system A status: CL
• Fuel system B status: --
• Calculated load value: 17.6%
• Engine coolant temperature: 172.40°F
• Short term fuel term - Bank 1: -1.6%
• Long term fuel trim - Bank 1: 7.8%
• Engine RPM: 673.00rpm
• Vehicle speed sensor: 0.00mph
• Intake air temperature: 91.40°F

I parked up again and cleared the code. I drove off, stopped, switched the engine off, and drove off again. The code came back whilst driving. Here's the freeze frame data for when the code came back whilst driving:

• Fuel system A status: CL
• Fuel system B status: --
• Calculated load value: 20.0%
• Engine coolant temperature: 172.40°F
• Short term fuel term - Bank 1: -0.8%
• Long term fuel trim - Bank 1: 9.4%
• Engine RPM: 1230.00rpm
• Vehicle speed sensor: 16.78mph
• Intake air temperature: 95°F

I also have the freeze frame data for when the code came back whilst idling outside my house a few days ago:

• Fuel system A status: CL
• Fuel system B status: --
• Calculated load value: 13.7%
• Engine coolant temperature: 203.00°F
• Short term fuel term - Bank 1: 4.7%
• Long term fuel trim - Bank 1: 14.1%
• Engine RPM: 640.00rpm
• Vehicle speed sensor: 0.00mph
• Intake air temperature: 131°F

I used an AutoLink AL619 to read and clear the code, and get the freeze frame data.

Something weird is going on. I’ve just gone out to the car to go out somewhere, and the code has vanished by itself. I didn’t clear it when I got back earlier.

Edit: Come to think of it, I may have cleared the code when I got back. I’ll keep an eye on whether it disappears by itself.

@orangejuice This is exactly everything that I am experiencing also. Literally every single detail. Not had the chance to check wiring from the ocv plug end to end yet as it has been poor weather this weekend. But I'm replacing my valve gasket when the weather improves. The other post you saw was mine from awhile ago. Still having the same problem

@flash22 If the wiring proves to be fine, do you believe that a partly blocked oil passage to the ocv would cause P1346? I will be popping off my valve cover to replace the gasket as it has been seeping oil into the plug channels.

the oil feed comes up the block through the ocv filter - OCV - VVT pulley and feeds back into the cams

OJ - last freeze frame - long-term fuel is pulling rich which is a sign that the timing is too far advanced at idle, almost like the ECU has no control over the OCV or the OCV is not responding to the PWM

38 minutes ago, flash22 said:

OJ - last freeze frame - long-term fuel is pulling rich which is a sign that the timing is too far advanced at idle, almost like the ECU has no control over the OCV or the OCV is not responding to the PWM

Thanks for the reply. Would replacing the OCV resolve this issue? What could be causing this issue?

1 hour ago, ShiftedReality1990 said:

@orangejuice This is exactly everything that I am experiencing also. Literally every single detail. Not had the chance to check wiring from the ocv plug end to end yet as it has been poor weather this weekend. But I'm replacing my valve gasket when the weather improves. The other post you saw was mine from awhile ago. Still having the same problem.

The problem is bugging me. I was hoping that the OCV is faulty as I can easily get a replacement.

May I ask how the wiring can be checked? I have no idea how to do this.

2 minutes ago, orangejuice said:

The problem is bugging me. I was hoping that the OCV is faulty as I can easily get a replacement.

May I ask how the wiring can be checked? I have no idea how to do this? 

You need to check the wiring from the ocv plug through the wiring harness. I'm not completely sure yet... but there is a main plug that plugs from the fuse box in the engine bay. You need to find what wires go from there to the ocv plug and find continuity through the wires. Flash22 has been suggesting I do this to rule out the wiring between the 2. I have my Haynes manual I'll be studying to find the correct wires. Once I get more information, I'll report back. I'll get some pictures tomorrow and post on here. I will post my freeze frame data so you can compare to mine too. 

I too noticed your LTFT is high on idle. Should be close to 0.0 as possible but yours is quite high at idle. A high Long Term Fuel Trim means a lean issue. This could be a few issues from vacuum leaks, clogged fuel filter or fuel lines, injectors or as Flash said, could be the timing too far advanced 

Any tips on how to diagnose the LTFT issue?

Oh, I found some recent pictures of my freeze frame data from my car at idle after a drive. I used my new Launch CR529 that I purchased a few days ago as an upgrade from my very basic 10 year old OBD scanner...

@orangejuice You can check for vacuum leaks by making sure that all the vaccum hoses are connected correctly, check the condition of the hoses to see if they are split or cracked. Listen for any air hissing around the hoses (difficult to do while the engine is running so you need a good ear) if any are found, replace. You can also spray brake parts cleaner onto the hoses and listen for any engine change, it might rev when spray around the suspected leak if any. 

The fuel filter is located inside the fuel tank at the back of the car under the rear seats. These aren't in the service schedule on the Yaris. I wouldn't recommend messing around back there unless you are confident enough to do it. 

Your injectors could be clogged and not providing the correct fuel to the combustion which is resulting in the incorrect air/fuel ratio BUT you'd probably notice with rough running and lack of power but you said your car runs fine so probably not that. 

The ocv may not be opening properly/ providing enough oil for advancement/!Removed! of timing so a new, decent OCV MAY solve that but worse case, your timing has jumped a bit which will require the chain to be changed and necessary parts with it and the engine retimed. Others on here will be able to provide better details but I'm going by what I've learnt from my amateur skills I've learnt over the years

I’ll pick up some easy/cold start fluid tomorrow and squirt it around the hoses. If the revs change at idle then hopefully that means I’ve found the vacuum leak. 

@orangejuice When you scan your car using your OBD scanner, does your P1346 come up as stored AND pending, or once it stores and your engine light comes on, it stays stored as the only fault? If that makes sense?