Your vehicle’s powertrain control module (PCM) is highly dependent on the data coming from the throttle position sensor (TPS), mass airflow (MAF) sensor, and manifold absolute pressure (MAP) sensor. The PCM uses the data of these sensors to ensure the efficient working of the engine. Whenever PCM detects an issue with any of these sensors, it triggers the P0068 code. This article mainly explains the P0068 code meaning, symptoms, and causes.
P0068 Code Definition
The P0068 code stands for “MAP/MAF – Throttle Position Correlation”.
What does the P0068 Code Mean?
The P0068 code triggers when your powertrain control module (PCM) detects a difference in the MAF sensor, MAP sensor, and Throttle position sensor (TPS) voltage values.
Your vehicle’s MAP sensor, throttle position sensor, and MAF sensor play a big role in ensuring the efficient working of the engine. Your vehicle’s PCM relies on the information of these sensors to control different functions efficiently.
A throttle position sensor tells the PCM how far the valve in the throttle body is open and how much air to draw into the intake manifold.
MAP sensor constantly measures intake manifold pressure and sends the data to your vehicle’s PCM.
The mass airflow (MAF) sensor determines the amount of air that is being ingested into the engine.
If reading from any of these sensors differentiates from the other sensor, then the Powertrain Control Module (PCM) sets the P0068 code.
Causes of P0068 Code
- Vacuum leaks
- Poor electrical connections at sensors
- Dirty air filter
- Intake leaks
- Bad throttle body
- Disconnected or clogged lines to the MAP sensor
- Damaged or bad MAF sensor
- Bad MAP sensor
- Bad throttle position sensor
- PCM issues
Symptoms of the P0068 Code
- Illuminated Check Engine Light
- Lack of power
- Rough idling
- Hesitation on acceleration
- Rough acceleration
- Poor fuel efficiency
- Hard to start the vehicle
- Stalling
Read More: P0053 Code Symptoms and Causes
How to Diagnose the P0068 Code
To diagnose or fix the P0068 code, you must have the following tools:
- Basic Hand tools
- OBD Scanner
- Multimeter
Follow the below-given steps to diagnose the P0068 code:
- Inspect and test the manifold absolute pressure sensor, the mass air flow sensor, the throttle position sensor, the intake manifold, and the air induction system.
- Use an OBD scanner to scan any other code in addition to P0068. If there are any other codes related to MAF, MAP, or TPS, then first find the cause of the other code and fix them.
- Inspect the air filter, and clean or replace it if needed.
- Visually inspect the connectors and wirings at the TPS, MAF sensor, and MAP sensor for damage or corrosion.
- Examine the intake connections and vacuum lines to confirm that lines are properly connected and there is no air leakage.
- Check for loose pipe clamps between the throttle body and the MAF sensor.
- Disconnect the intake pipe from the throttle body and check the throttle body for carbon accumulation.
- If your throttle body is dirty, clean it and clear the code.
- If the MAP sensor is located remotely from the intake manifold, ensure that air passes through the vacuum lines feeding it.
- Start the engine to evaluate if there is any hissing sound.
Common P0068 Code Diagnosis Mistakes
The following are the most common DTC P0068 diagnosis mistakes:
- Replacing fuel or ignition system parts by assuming the issue is a misfire
- Replacing any sensor without testing its functionality before the replacement
- Replacing the unnecessary parts
- Not clearing the trouble codes after necessary repairs
What repairs can fix the P0068 Code?
Repairs that can fix the P0068 code would include:
- Replacing the throttle body sensor
- Vacuum leaks repairs
- Replacing damaged connectors
- Replacing or repairing the MAS sensor
- Inspection for clogging and dryness
- Replacing or repairing the MAP sensor
- Examining sensors for resistance and voltage
- Replacing or repairing the damaged wiring
- Adjusting the mounting or installation of the MAF sensor, MAP sensor, or TPS.
- Inspect the sensors for corrosion.
- Checking the PCM for issues
Repair Costs for P0068 Code
The repair or fixing cost of the P0068 code varies according to the vehicle model, labor cost, and repair cost of the relevant part. To fix or repair the P0068 code, you may need one or more of the following repairs:
| Parts | Cost |
|---|---|
| Intake/vacuum leak fixing | $140 to $260 |
| Air filter replacement | $30 |
| Wiring replacement | $90 to $1100 |
| Throttle body cleaning | $220 to $300 |
| TPS replacement | $160 to $240 |
| MAP sensor replacement | $50 to 180 |
| MAF sensor replacement | $90 to $400 |
How serious is the P0068 Code?
The P0068 code may not be serious at first, but it can lead to a severe issue in your vehicle. With this code, your vehicle will not run efficiently and will consume more fuel than usual. You may also face rough acceleration.
The rough acceleration for a long time may damage your engine. It is recommended to diagnose and fix this problem as soon as possible to avoid further engine damage.
FAQ Section
How to reset the throttle position sensor?
The easy method to reset the TPS is to disconnect the negative battery cable for about 5 minutes or remove the fuse in the Powertrain Control Module.
What happens when you unplug the throttle position sensor?
When the throttle position sensor is disconnected, the PCM cannot properly control the amount of fuel it delivers to the engine. Also, your engine may start to consume more fuel than usual due to that; you may face poor fuel economy issues.
Where is the throttle sensor position located?
The throttle position sensor is installed to control the intake air volume of the engine. It is frequently located on the throttle spindle/shaft, so it can directly measure the throttle position.
Can a throttle position sensor lead to transmission problems?
The throttle position sensor calculates the throttle position regulated by the accelerator pedal. This sensor is also used to calculate engine load. As it goes bad, it can produce automatic transmission shifting issues.