The S2000 MAP sensor in your Honda is there to provide real time readings on the barometric pressure if your intake manifold. This sensor takes the vacuum readings from your intake and sends this data to your S2000 ECU or Engine Control Unit. Based on this signal your Honda ECU can properly control the fuel curves for optimum fuel efficiency.
When this sensor goes bad or sends a signal that your ECU doesn’t expect, it can cause big problems. One of the first Honda S2000 problems you’ll notice is the check engine light turning on in your instrument cluster.
When you see your S2000 check engine light turn on, you’ll need an OBDII scan tool to check what the code is.
If the OBDII trouble code shows that your manifold absolute pressure sensor is to blame, this is the How To guide you need. Today I’ll be showing you how to test a S2000 MAP sensor in a 2003 AP1 Honda.
This vehicle has a check engine light on for the MAP sensor being out of range. Using a digital multimeter, you’ll be testing the operation of your pressure sensor. Again if there’s a lot of common Honda S2000 issues when your pressure sensor goes bad.
Symptoms of a failed S2000 MAP Sensor
When this pressure sensor in your 2.0 liter F20 engine goes bad, your Honda will start to show some common S2000 issues.
- Bad gas mileage
- Engine runs lean or rich
- Engine misfire
- S2000 hard to start
- Check Engine Light ON
Some of these problems range from annoying to severe, which is why we’ll be starting by checking the S2000 MAP sensor for power.
Checking your S2000 MAP sensor for power
Begin by turning the ignition in your AP1 S2000 to the “ON” position. Now open your hood and locate the MAP sensor, mounted to the throttle body. Once you’ve located the MAP sensor ( don’t confuse it for the throttle sensor ) disconnect the three pin weatherproof connector.
Using your digital multimeter, measure the wire that leads to PIN O for a 5 volt signal. Do this by putting the black lead on the negative battery terminal, and gently probing the front of the MAP sensor connector.
This wire should be YELLOW with a RED stripe in it.
If you see a power signal at this wire, the next thing to check is the ground. Switch around your multimeter leads to check for a ground signal at the wire of the MAP connector at PIN V.
This wire should be GREEN with a RED stripe in it.
The ground signal should be present at this wire, and if it is this means that your S2000 MAP sensor is powered correctly.
The next part of our How To guide is to check the voltage at the MAP sensor. Reconnect the MAP sensor connector and pierce the middle wire with your red multimeter lead. With the engine off and your ignition at the “ON” position, there should be between 2.8-2.9 volts of signal.
Now keep your hands clear of your engine and cooling fans. Start your S2000 engine and monitor the voltage at this wire. As you increase the engine speed, and you should see this signal voltage sweep smoothly, without any spikes or dips in voltage.
If this part checks out the last leg of our DIY tutorial is to unplug the MAP sensor, and put a jumper wire between PIN 2 and 3, or PIN G and V as shown in our wiring diagram.
With a jumper wire installed between these two wires, go back and reconnect your OBDII scan tool.
Select the real time viewer using your scan tool. Highlight the MAP sensor or pressure sensor value and check for at least 101 kPa or 760 mmHg. If your OBDII scan tool does not display this value, it should show at least 2.9 V or higher.
If your S2000 MAP sensor doesn’t respond in this manner, you need to remove the failed sensor. Install your new S2000 manifold sensor and use a OBDII scan tool to clear your trouble code.
Have any questions about your Honda S2000 MAP sensor? Leave us a comment below and let us know!
My s2000 bogs at idle but my map tests okay. What else could this be?? Thanks guys
Hi Jason! thanks for reading!
What symptoms is your AP1 exhibiting? will it idle okay normally? Does it bogging happen after you let off? Have you checked for intake leaks in your Honda? Let us know and we’ll be glad to help out!
Your write up definitely helped me understand that it is MAP issue. Now whether its the sensor or wiring, thats the question? When disconnected, O is 4.95VDC but could not find continuity to negative terminal or ground at V. When connected G gives variation of less than 1V then a sudden spike at the end of revving down. Rechecked 3 times, same results. I’m exhausted?
Hi HK,
Okay, so let me try to understand. You are measuring the MAP sensor harness and getting 4.95V at pin O, which is normal. But you don’t have a ground and that’s the issue. If you don’t have ground at the V pin, then you’ll need to find where the issue is. It’s best to check the ECU first, and ensure that all grounds are intact. Your ECU should have a cluster of chassis grounds under your dash, start there. You can also ground this wire and see if the MAP sensor starts acting like it should.
Hope that helps!
Hey so sorry if this has nothing to do with the map sensor. But i recently changed my O2 sensor, knock sensor, spark plugs as i had codes for both sensors. My cel went away for a day and two new codes came back the next, P0172 and P0170. I looked at some forums and some say it could be the map sensor or a bad o2 sensor. Just t wondering if anyone knows what the issue could be.
2002 AP1
Hi Brandon,
I would start with a multimeter and test your S2000 MAP sensor first using this guide. The codes you mentioned are for an overly rich condition, so if the MAP sensor is good the next thing to check is your primary 02 sensor.
Hope that helps.