Error code P1346

Welcome to 2CarPros.

Take a look at picture 1. For this code, it indicates either a timing issue or ECM. If this wasn't an issue prior to the replacement of the belt, I suspect that for some reason, timing is off. I attached another picture. Is that where the timing marks are located with the engine cold?

Let me know.

Joe

Welcome back:

If the engine is running that well, I suspect the timing is correct. However, VVT can be somewhat tricky. As far s the ECM, we will need to identify specifics as far as what we need to check. The ECM has a multitude of connector pins that need identified and then checked one at a time.

Welcome back:

What I suggest first is to disconnect the ECM main harness and check it. Before you disconnect the ECM, first disconnect the battery and don't reconnect the battery until the ECM has been reconnected.

Inspect the ECM connections both at the plug and the ECM for damage, corrosion, or anything that can prevent a good contact.

Joe

Welcome back:

I have to assume yes. Your vehicle doesn't have a PCM, so I'm questioning what you are seeing. Older vehicles have an ECM which is responsible for some of the engine controls. Newer vehicles have a PCM which basically controls all of them.

If you look at the picture I attached, it is right from Alldata. Let me know if something is different than what you are seeing.

Joe

Welcome back:

I attached a picture showing how it comes apart. Let me know if it helps.

Joe

Hi again:

Is it the same code that returned? If it is, we know the code indicates a variation in VVT timing between the crankshaft and camshaft VVT sensor bank 1. I honestly suspect it is a mechanical issue such as a stretched timing belt. It is either a timing issue (stretched belt or off a tooth) or the ECM is bad.

If you look at pic 1, it shows the flow chart for troubleshooting the problem.

In my mind, there is more than this. It could be an oil pressure issue not allowing the VVT actuator to function properly, a dirty or partially plugged timing oil control valve (one for each bank) or even dirty motor oil.

Before I suggest replacing the ECM or taking everything apart to check timing, I have one last suggestion. I would like you to check the timing oil control valves.

Here are the directions for testing them. Picture 2 correlates with these directions. All you are doing is checking resistance in the sensor itself.

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2001 Lexus Truck RX 300 AWD V6-3.0L (1MZ-FE)
On-Vehicle Inspection
Vehicle Powertrain Management Computers and Control Systems Variable Valve Timing Actuator Testing and Inspection Component Tests and General Diagnostics Camshaft Oil Control Valve On-Vehicle Inspection
ON-VEHICLE INSPECTION

pic 2

INSPECT OIL CONTROL VALVE RESISTANCE
a. Remove the V-bank cover.
B. Remove the intake air connector.
C. Disconnect the oil control valve connector.
D. Using an Ohmmeter, measure the resistance between the terminals.

Resistance: 6.9 - 7.9 ohms at 20 °C (68 °F)
If the resistance is not as specified, replace the valve.

E. Reconnect the oil control valve connector.
F. Reinstall the intake air connector.
G. Reinstall the V-bank cover.

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If you find the specs within the manufacturer's specs, we will then need to check the timing.

Let me know what you find. Also, sorry for all the different tests. However, I don't want to make a suggestion, be wrong, and do nothing but waste your money.

Take care,
Joe

Hi:

Sounds like a plan. I will watch for your reply. Let's hope it is one of the oil control valves. It will be much easier to deal with. LOL

Take care,
Joe

Hi,

When checking resistance, you can remove it because all you are checking for is to see if there is a break down in the unit. The DMM (digital multi meter) supplies power.

Feel free to let me know if I can help. Also, if I don't hear from you, have a great Thanksgiving.

Take care,
Joe

If you are getting a signal from the ECM, it should be okay which leaves a few things. Based on the idea that it runs really well, I was leaning toward an ECM issue. If you made a mistake on the timing, it wouldn't be running as well as you described. Which only leaves a couple things, sensor, ECM, bad connection.

Have you checked the signal to the sensor?

Hi,

If you were checking ohms, that is different because the power was supplied via the multi meter simply checking resistance. I may have asked this already, but do you have a scanner that can provide freeze frame data? If so, read freeze frame data using an OBD II scan tool, because freeze frame records the engine conditions when the malfunction is detected, it will be useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. At the time of the malfunction. As far as checking the ECM, basically the directions indicate to check for an open or short in the wiring between the sensor and the ECM. If no problem is detected, replace the ECM.

Take a look at the flow charts I attached. See if anything helps.

Let me know.

Joe