Virtual torque management system (VTM-4) on 4-wheel drive Honda Pilot SUV automatically detects the traction conditions and distributes engine torque to the axles accordingly.
What causes the Honda Pilot check engine light VTM-4 to come On? There are several reasons for the appearance of VTM-4 and check engine light on Honda Pilot. Direct causes can be the low engine oil pressure, VTM oil temperature sensor, and damaged or improperly installed gasket. There can be indirect reasons like faulty oil pressure sensors, oil pressure switch, and exhaust gas recirculation (EGR) valve. You also need to check the condition of the transmission fluid to diagnose the real problem.
What is VTM-4 on a Honda Pilot?
VTM-4 is an automatic torque control system introduced by Honda. Road traction conditions change the applied torque to the rear axle to get optimum road grip on slippery or snowy surfaces.
It remains active as soon as you turn ON the engine and automatically perform its function without driver input.
If your vehicle gets stuck in extreme mud or snow, you can manually activate the VTM-4 by pressing the lock button in front. It provides maximum torque to the rear wheels.
However, before pressing the lock button, the Honda pilot should be in the first, second, or reverse gear, and the speed should be below 17-19 miles per hour.
Engaging the VTM-4 lock on highways or smooth surfaces can damage the rear differential at turns.
You can also observe strong vibration and noise due to the locked axle. Therefore, use the function only when necessary and allow the automatic system to adjust the torque to axles by itself.
Causes of Check Engine Light and VTM-4 Light to Come On
An engine symbol on the dashboard indicates any fault in the engine and is called a check engine light. VTM-4 symbol blinking or turning on the dashboard indicates its problem.
Sometimes, both lights turn ON simultaneously. It can result from several reasons, including issues in any relevant systems.
Low engine oil
First, use a dipstick to check the engine oil level. If it is up to the recommended level, next check its quality.
In case of dark-colored or excessive black debris, replace it with the manufacturer’s recommended oil.
Most of the time, it will resolve the indications on the dashboard. Furthermore, there is a possibility of oil leakage in the case of low oil levels. Therefore, before a refill, you need to find the leakage and rectify it.
An oil pan gasket is a part that seals the oil pan to prevent any oil leakage underneath the engine. It wears out with time and starts leaking oil. It results in low engine oil levels.
A loose or improperly fitted gasket can also cause similar problems. Other possible causes for its damage are road debris, grease leaking from different parts, and undersized design.
Besides signs of an oil leak, another symptom of a bad oil gasket is smoke coming from the engine compartment.
Therefore, you should inspect the oil pan gasket and replace it in case of low oil levels or any symptoms of oil leakage.
Oil pressure sensors
The third major cause for check engine and VTM-4 lights both ON is the malfunctioning of oil pressure sensors.
When scanning with a diagnostic tool, you will get a P3400 trouble code. It indicates a problem with oil pressure sensors.
If you change the engine oil regularly and its level is proper, then the indications on the dashboard are due to faulty sensors. You can replace them or swap them on both cylinder banks to view the results.
Rocker arm oil pressure switch
PCM uses a rocker arm oil pressure switch to monitor oil pressure and activates the variable timing mechanism of valve control accordingly.
There are 2 of them on the front and rear sides of the engine. It is also an oil pressure sensor, and you will get P3400 for the backside or a P3497 fault code for the front side sensor.
While replacing the switch, remember to install the appropriately sized O-ring that comes with it and also check its wiring connector for any broken wire.
Exhaust gas recirculation valve problem
The exhaust gas recirculation (EGR) valve has no direct connection with VTM-4 regarding its operation.
However, its malfunctioning can sometimes result in multiple fault codes and indications on the dashboard.
It controls the harmful Nitrogen oxides emissions in the environment by recirculating a part of exhaust gases to the combustion chamber according to engine load.
PCM controls its operation according to the driving conditions. It’s malfunctioning due to poor quality gasoline, or solenoid problems.
The ultimate solution is to replace the EGR valve and reset the fault codes to resolve the error indications on the dashboard.
Expired transmission fluid
VTM-4 is a traction control system and has a close link with the transmission system of the Honda Pilot SUV.
Therefore, transmission fluid should be changed regularly and in good condition to prevent maintenance issues.
Low transmission oil level or increase in its temperature can result in a check engine and VTM-4 light on the vehicle.
If transmission fluid is up to the mark, then check its quality. You can observe its quality by its odor and color.
If it has a burnt smell and cloudy or milky color, it is expired or has water content. Therefore, flush the transmission system and change its fluid with the recommended oil brand.
Bad idle air control valve
If you observe rough idling of a Honda Pilot with both check engine and VTM-4 lights ON, then the problem can be a bad idle air control valve.
PCM controls the valve to regulate the airflow to the motor for smooth idling. Other symptoms of the fault are engine stalling and vibrations during vehicle movement.
Therefore, replace the valve and reset the system to reset the fault indications on the dashboard.
VTM-4 Oil Temperature Sensor
The VTM system needs fluid for lubrication and cooling in the rear differential for its smooth functioning. In case of a low oil level or high temperature, you will get these issues.
If changing the VTM fluid does not resolve the fault, then the problem can be in the temperature sensor. You can locate it in the rear differential sump to measure its temperature.
If the light persists after the sensor replacement, visit any authorized dealer to read fault or trouble codes and apply remedial fix accordingly.
How to diagnose the check engine and VTM-4 light issue?
The Honda Pilot system has a VTM-4 control unit that keeps records of the last 7-8 faults or trouble codes. You can read them using a compatible diagnostic tool (OBD-I or II) or scanner.
Each code tells the associated part of the problem. It makes the diagnostic procedure easy and pinpoints the faulty component.
Based on their experience, expert technicians can rectify the fault by recalling such fault codes or symptoms they observed in the past.
VTM-4 has a self-diagnosis mode. In case of any abnormality, it turns the light ON and saves the trouble code.
It stops the 4WD configuration, and the vehicle will operate only in 2WD until you resolve the problem. This adjustment ensures the safety and prevents any damage to the rear differential system.
The cost to repair varies according to the faulty component and services hired.
If you fix the problem yourself by seeking help from online forums and YouTube and purchasing parts, it will cost less than $100 for such a fault.
However, hiring services from a workshop will cost around $200-$300 in terms of labor and spares.
Can you drive the Honda Pilot with the VTM-4 light On?
You can drive a Honda Pilot SUV with VTM-4 light in ON condition. The system has a self-diagnosis mode to limit its capability during any fault but keep it running in 2WD instead of 4WD.
Moreover, in most cases, an indication results from any false signal or power glitch. You can quickly resolve it by switching the vehicle OFF and then ON.
How to reset VTM-4 on a Honda pilot?
To reset or disengage the VTM-4 lock, you need to press the lock button again. Secondly, move the shift lever to the drive or D position.
The last step is to turn the key in the ignition switch to the OFF position and then restart the vehicle.