CEL help Options

[bmj67]

I have a 99 gt manual and my CEL came on so i had a friend put a computer on it to see what codes were coming up and i got a P0340 camshaft position sensor A bank 1 malfunction and P0500 vehicle speed sensor A malfunction. When i rev the engine it will go up to 4k and then cut out. I checked the resistance on the cam sensor and it was within limits and the air gap was fine as well. I know the speed sensor is on the trans but unsure exactly where. How can I test the speed sensor. If anyone has any ideas of what to check for please let me know.

[Bitter]

http://www.obd-codes.com/p0340

[bmj67]

thanks for the link. it says to check cam position sensor voltage do you happen to know what it should be? i did not see it anywhere in the bgb manual that i got from griffgirl

[Bitter]

iirc it should be an AC voltage that ramps up, spikes, and then drops....due to the shape of the lil trigger wheel. dont know what its exactly supposed to be off the top of my head.

i do know that the sensor is part of the distributor and you change the whole thing.

[hurley97]

According to the 97 BGB I have:
P0340 DTC Detecting conditions: No camshaft position sensor signal to ECM during cranking (2 trip detection logic) AND/OR No camshaft position sensor signal to ECM with engine speed 600 rpm or more.
Trouble areas: Open or short in camshaft position sensor circuit; camshaft position sensor; starter; ECM

The resistance for the pickup coil in the distributor should be as follows:
cold: 135-220 ohms
hot: 175-255 ohms

and for the crankshaft position sensor:
cold: 985-1600 ohms
hot: 1265-1890 ohms

[bmj67]

I checked the resistance earlier and it is within spec. So I just went and pulled the harness from the ecu and checked the wires for and shorts and there were none. Is it possible that if the speed sensor is bad it could cause the cam sensor code to show up. I know they are completely different sensors but I don't know how the ecu processes the signals.

[Bitter]

they are fed power on the same circuit, atleast in the camry they are.

[bmj67]

so does that mean that one can cause the other?

[Bitter]

no, that means that they could be related. are you getting power at both?

wait, my bad. i got my repairs confused i think...it was the alternator and speed sensor that got a power feed on the same circuit. its been a few months so its a little fuzzy.


check out some wiring diagrams, that should clear it up.

This post has been edited by Bitter: Nov 2, 2008 - 10:04 PM

[bmj67]

Well I found that i had a bad crankshaft sensor and I replaced it but I am still getting the P0340 code. Is there anyway that I can test the ecm without resorting to buying a new ecm. I cant justify buying the ecm if it is not the problem and then being stuck with it. I don't even know of anyone else with a 6g with M/T and obdII in the area to try a quick swap

[Bitter]

replace the camshaft sensor.

[bmj67]

The camshaft sensor tests in spec and the air gap is good as well

[Bitter]

can still be a problem with the sensor itself or the circuit, test from the pcm end of things.

[bmj67]

I checked the circuit at the correct pins on the ecm with a multimeter and the resistance of the sensor was within the range that the manual specifies. Is that the test that you were referring to

[Bitter]

more or less, yes

[PizzaGuy01]

Sorry for bringing this back from the dead, but did you ever sort out the problem? I have the exact same issue with the speed sensor and cam sensor codes, except my engine pulls to redline. I did have a temporary issue where the ecu was pulling %25 fuel regardless of the O2 sensors being plugged in or not, but now the only issue is those same two persistent codes you had.