Q: 2008 Mazda 5 has codes P0661 and P0720

asked by on January 31, 2017

I've engine fault lights up, so I went to nearby workshop to check. He used a wireless device to test and the error code is P0661. He cleared the error and I ask me to come back if error comes out again. The next day the engine fault lights up again and then goes off the next day. I ignore and continue to drive for a week. Then suddenly while on the highway, the engine fault and AT lights up, the car jerk a little then AT light goes off. But the engine fault remains on. I went to another mechanic, this time the computer they use is wired type. The error fault they found now is OSS, and I couldn't remember the code. It could be be P0720 or P0721 etc. He replaced the speed sensor. I thought the issue solved but two days later the car jerk at the highway again. The AT lights up followed by engine fault lights up. The AT light then goes off. These light keeps going on and then off again the next day or day after. What do you think the root cause can be? Could it be the Gearbox spoil?

My car has 130000 miles.
My car has an automatic transmission.

Input from the vehicle speed sensor (VSS) is used by the transmission control module (TCM) to calculate shift points, torque converter operation and other transmission functions. Code P0720 stands for Vehicle Speed Sensor circuit malfunction. Typically, this code indicates a problem with the VSS circuit and not an internal transmission problem. If the problem continues even after sensor replacement, the issue is either the circuit wiring or the transmission control module. Code P0661 stands for Variable Intake Air System Solenoid Circuit Low Input and is not likely to be related. I recommend getting a second professional opinion on the issue, sine the initial shop was not able to fix the problem. YourMechanic is an excellent option for your check engine light diagnosis because we come to your home or office.

Was this answer helpful?
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

Get a quote

What others are asking

Coolant compatibility in f350.

Hello. I am not sure why they put Dexcool into your cooling system. Your truck requires the specific Ford coolant due to the design of the engine. There really is no reason why Dexcool should have been used, and if...

Well the check engine light is blinking. A track light keeps coming on and there seems to be loss of power. Engine running rough.

Hello. If the check engine light is flashing then that typically means that there is a cylinder misfire. This can be caused by a bad spark plug, spark plug coil, or fuel injector. It can also be caused by something...

Leak in radiator.

I would ask for help from one of the mechanics at YourMechanic. They can come to you and perform a pressure test of your cooling system and determine if there is a leak in your radiator that needs to be...

Related articles

P0740 OBD-II Trouble Code: Torque Converter Clutch Circuit Malfunction
P0740 P0740 Code Definition Torque converter clutch circuit malfunction is the technical definition of this trouble code What the P0740 code means What the P0740 code means is that the powertrain control module (PCM) has detected something unusual within the...
P0259 OBD-II Trouble Code: Injection Pump Fuel Metering Control "B"
What What the P0259 code means The powertrain control module (PCM) has recognized a discrepancy in the signal voltage that is supplied to the electronic fuel control actuator and the signal returned from the fuel metering control sensor. Please note...
Symptoms of a Bad or Failing Neutral Safety Switch
Common signs of a faulty neutral safety switch include the engine not cranking in park or neutral, not cranking at all, or cranking in any gear.