Q: MAP sensor

asked by on December 27, 2017

My 2001 volvo s60 has 246,000 mile on it in good condition when I drive it jerks really hard or when stop at a red light to long it jerks what can this be

My car has 246000 miles.
My car has an automatic transmission.

This may be a sign of a faulty MAP sensor as the vehicle responds adversely to a load put on the motor (i.e. putting it in gear, making turns (which makes use of the power steering pressure switch) turning on AC or engaging the brakes). The Manifold Absolute Pressure (MAP) sensor senses engine load and generates a signal that is proportional to the amount of vacuum in the intake manifold. The engine computer then uses this information to adjust ignition timing and fuel enrichment. When the engine is working hard, intake vacuum drops as the throttle opens wide. The engine takes in more air, which requires more fuel to keep the air/fuel ratio in balance. When the computer reads a heavy load signal from the MAP sensor, it adjusts the fuel mixture to slightly more rich than normal so the engine can produce more power. The computer will then retard (back off) ignition timing slightly to prevent detonation that can damage the engine and decrease performance. This may also be caused by other closely related components such as a dirty or failing mass air-flow sensor, a faulty throttle position sensor or potentially a vacuum leak. I would recommend having an expert from YourMechanic come to your location to diagnose and inspect your vehicle.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

What others are asking

passing gear not working

The transmissions in these vehicles have a long list of possible causes for the concern that you are having. They include the valve body not controlling the down shift and the valve body needing to be removed and cleaned out...

Car making noises while driving

If your car is making a clunking or rumbling noise, I suspect that perhaps a wheel bearing or CV axle has failed. However, it would be hard to properly diagnose this issue without an in-person inspection. I would recommend having...

Car won't go - 2001 Honda Odyssey

Hello, thanks for writing in. Unfortunately, without additional detail as to the specific symptoms you are experiencing or any potential indication of warning lights, etc. This may be difficult to diagnose without physically inspecting the vehicle. I would recommend having...

2001 cavalier sputtering while driving.

Hi there. Try pumping out all of the fuel from the fuel tank and filling the tank up with fresh fuel. If the water remover was put in the tank and the vehicle started to run a little better, then...

my gas mileage is decreased and i have random misfires, noisy lifters when cold but noise goes away once fully warm . o2 sensor?

Hi there. Thanks for writing in to YourMechanic.com about your issues the Toyota is experiencing. It is possible that you have two, independent problems that are causing two unique symptoms; the random misfire and the fuel economy issue. Although faulty...

My car only overheats when ac is on?

If you have overheating only when you have the A/C on then you most likely have a bad fan clutch. The fan clutch should lock up when the added heat from the A/C is added from the condenser to the...

can the pcm/ecu/ecm drain the alternator

No, the alternator provides voltage to the battery and other components. The PCM could possibly discharge a battery if it leaves a relay or another circuit on, but most likely is is not the cause of your alternator failure. If...

I have a 2001 5.4 Ford F150. The oil pressure light & gauge is on.

Hello there, many common faults will result in your oil pressure gauge reading only after a few minutes and the Oil Pressure Light being on in your 2001 Ford F-150. The most common fault that would cause this is low...

OBD not working

Hi there. If the OBD port is not working then most of the time this is caused by a loss of power to the plug. The fuse to the plug needs to be checked first to see if it is...

Related articles

A Buyer's Guide to the 2012 Volvo S60
When When it comes to safety, no automobile manufacturer can hold a candle to Volvo. With their 2012 S60, the popular brand added some real character and a lot of great features, too. If you want a sedan that compares...
A Buyer’s Guide to the 2011 Volvo S40
When When you think of Volvo, safety undoubtedly comes to mind first, and that’s exactly what the 2011 Volvo S40 is all about. Of course, it’s also comfortable, refined and features a pretty high-performing engine, to boot. You might actually...
The Best Used Cars to Buy If You're a Dog Trainer
If If you are a dog trainer, you expect a lot from your vehicle. You want a ride that is safe, roomy, and of course, dog friendly, since your training operation will often mean that you need to transport the...