Atmospheric Pressure Sensor

I have a 1989 Honda Prelude SI, 5 speed, 2.0, FI, DOHC, that will not start. The LED in the ECU gives a error code of 13, Atmospheric Pressure (PA) Sensor circuit. I have looked everywhere and can not find this sensor. I need help. Does anyone know where it is?

There are several possibilities. Its probably describing the MAP sensor which can be on the firewall, on the intake, or (rarely) inside the computer.

Thanks Cutris. The MAP sensor is on the firewall and its error codes are 3 or 5. The error code I am getting is 13, which my information says is the Atmospheric Pressure sensor.

Well, I learn something new every day. Why does it have an atmospheric sensor on an 89? I thought that was strictly OBD2...

I do not know for sure that it has an Atmospheric Pressure sensor. In fact, I can not find it. The only thing for sure is that I am getting an error code of 13. Any suggestions?

Halleluiah, I found it. My atmospheric pressure sensor is located under the dash, near the glove box and the ECU. A new sensor cleared my #13 error code and fixed half my problem.

So are you saying you replaced it and the car started?

No, it fixed half of my problem. It still will not start. I also get a 15 error code, Ignition Output Signal. Voltages at the Igniter unit check OK per the Troubleshooting Flow Chart in my Honda Service Manual.

The error code 15 only shows after cranking the engine. After resetting the ECU, the error codes does not show again when the ignition switch is turned on, only after the engine is cranked. The troubleshooting flow chart says: “Intermittent failure, test drive may be necessary.” I surely would like to do a test drive, but the engine will not run.

Does anyone have any suggestions?

Thanks!