brajohns

Hi all,
Been reading this forum for a while but this is my first post. Yesterday as I was pulling into a parking spot, my car just died, like someone had disconnected the battery. Then at the end of the day when I was leaving, the CEL came on when I started the car, and it was really hesitating/misfiring when I put gas to it. I turned the car off and restarted, it drove normally, and was able to make it home without any problems. I took it to Autozone to get the code checked, and it was P0108 - Map / BARO High Pressure. Now, I had this same code about 6 months ago. I replaced the map sensor, and it fixed the problem (temporarily I guess). I also changed the fuel and air filter and that made things run a lot better too. It's a 98 CL 3.0, with 151,000 miles. Any advice?

swiftt5389

still on the original tranny??

brajohns

Yep...

Eband27

wow. 151.000 miles on original tranny. :-0

brajohns

Yeah.. haven't really noticed any problems with it either. It shifts kinda hard when putting it into drive or reverse, but I don't notice any slipping or anything like that when driving it.

TexasHonda

P0108 diagnostics are available in most Honda shop manuals. Boiled down they mean either a fault in wiring, connector, or sensor. You may want to return the MAP sensor for a replacement, since this fixed the problem for 6 months. Some wiring check should be performed to verify this is not the problem.

good luck

brajohns

Thanks for the info Texas. I don't have a shop manual. Is there a troubleshooting diagnostic online somewhere? Is it possible I have a vacuum leak?

TexasHonda

Suggest downloading the 94-97 Accord manual from hondahookup.com. This has diagnostics for Code 3 which generally corresponds to your problem. Should be good enough. Combined w/ a Haynes manual for your model, this provides good coverage for this and other problems.

Based on this manual, I doubt a vacuum leak would cause the P0108 code. A loose vacuum line would cause manifold absolute pressure (MAP) to be always equal to atmospheric pressure. This would cause a low voltage output from MAP sensor. Code P0108 is high input which suggests faulty sensor since MAP can't always stay low (high voltage input to ECU).

good luck

brajohns

I downloaded the manual and found the diagnostics. It looks like I will need a test harness. Are these available at auto parts stores, or do I have to get one from Acura?

brajohns

I tested the voltages, and Yellow/White to Ground was 3.59, Yellow/White to Green/White was 3.59, and Green/White to White/Yellow was 5. The manual says these should be approx 5V each. Is 3.59 acceptable, or is it different between the 94 Accord manual I'm using and the 97 CL car I have?
Hope someone has an answer...

TexasHonda

I've had similar experience measuring voltage. They never match circuit values or diagnostics. Your VOM impedance may be too low and loading the circuit (1 megaohm or more is necessary) . Are you measuring on lowest possible voltage range?

No test harness is available to my knowledge. I would try to either backprobe (fine wire) or quick splice yel/wht and measure output signal w/ high impedance VOM w/ engine off and running. There should be a lower voltage w/ engine off than w/ engine running, perhaps 1V or more. Again, a high impedance meter is probably necessary to measure correct voltage.

The quick-splice is an electrical wire splice that folds around an auto harness wire and splices a new wire to the harness wire when you fold the splice and close the latch on the splice.

good luck