df115 4-2 fault

[Wwarden5091]

I am fighting a "no start" issue with a 2006 df115 with 759 actual hours, I have been troubleshooting using ver 8.0 sds unsuccessfully. I know it indicates a ckp fault. I have changed the ckp sensor 2 times and the camshaft sensor 1 time. Have checked wiring from both those sensors to the ecm including sensor gnds and all appears to be well there. CKP, emerg switch, and ctp switches operate normal as indicated by SDS. Sometimes it will try to start but not very often. All actuator tests check good iaw SDS. Got 5 fails on CKP sensor, 3 fails on cmp, and 2 fails on IAT as logged by SDS. Visual inspection of all wiring, fuses, clean battery connections have been done also. Any help is greatly appreciated as there are no suzuki service center close to me at all.

[redlowrey]

I am fighting a "no start" issue with a 2006 df115 with 759 actual hours, I have been troubleshooting using ver 8.0 sds unsuccessfully. I know it indicates a ckp fault. I have changed the ckp sensor 2 times and the camshaft sensor 1 time. Have checked wiring from both those sensors to the ecm including sensor gnds and all appears to be well there. CKP, emerg switch, and ctp switches operate normal as indicated by SDS. Sometimes it will try to start but not very often. All actuator tests check good iaw SDS. Got 5 fails on CKP sensor, 3 fails on cmp, and 2 fails on IAT as logged by SDS. Visual inspection of all wiring, fuses, clean battery connections have been done also. Any help is greatly appreciated as there are no suzuki service center close to me at all.

How capable are you at voltage drop testing with a digital multimeter, these early fuel injected engines are very simple to diagnose problems for an auto electrician, you don't need to go to a suzuki dealer.
The crank sensor is just a two wire inductive sensor that uses magnetic induction to produce an ac voltage that will be digitalized inside the ecu, and the cam sensor is a three wire sensor with a power signal and ground that produces a square wave on off signal. tell me how you tested the sensors and what voltages you got, and a little bit of history on the motor.

[Wwarden5091]

I only have .6vdc on the red/bk wire with ckp disconnected. Also have same voltage at back of ecm plug. Resistance of all 3 ckp,s i have tried are the same around 200ohms if i remember right. Engine will "hit" occasionally but not run and continues to give 42 fault both on sds and check engine flashes. Sds also indicated iat fault but found intermit wire at temp probe and fixed that but ckp fault remains.

[Wwarden5091]

Cam sensor i tested by leaving pluged in, removing, and passing socket near it and voltage reacted on center signal wire. I also changed it out

[redlowrey]

I only have .6vdc on the red/bk wire with ckp disconnected. Also have same voltage at back of ecm plug. Resistance of all 3 ckp,s i have tried are the same around 200ohms if i remember right. Engine will "hit" occasionally but not run and continues to give 42 fault both on sds and check engine flashes. Sds also indicated iat fault but found intermit wire at temp probe and fixed that but ckp fault remains.

Obviously you didn't read my post properly, you might have trouble reading a dc signal when the meter should be on AC.

[Wwarden5091]

1.6vac while cranking

[redlowrey]

Is the engine cranking over fast, normally the computer would need to see minimum 2 volts peek to peek, is that peek to peek on your meter or rms. What size gap have you between the sensor and the fly wheel, should be around 30 thou or .75mm.
Do this simple test, remove the plugs from the coils, remove the spark plugs and crank the engine and see if the ac voltage increases with the crank sensor unplugged, make sure you check the gap between the sensor and fly wheel. If the voltage increases plug the sensor together, use a low powered test light connected to ground then then turn the key on you should have power on the gray wires on each plug, then connect the test light to battery pos, crank the engine and probe the other pin and if the crank sensor is switching the light should blink.
When you test the cam sensor you should see a five volt peek and no more than 100mv on the ground on the signal wire.

[Wwarden5091]

Thanks for the info and your patience. Im pretty sure the air gap is larger than .30. Ill get that right first, tomorrow, and continue on with the new checks you just outlined for me and let you know results. Thanx again!

[Wwarden5091]

Went out first thing this morn and using your instructions had exactly 2.0 VAC as measured with a traditional digital multimeter. When i plugged the CKP back in it still remained at 2vac as measured at back of ecm plug. CAM sensor read 5 vdc on signal og wire (center) and .16 on bw side. All measurements taken at ecm plug. I did not do test light procedure as the ac volts did not increase unplugged or plugged in. I hope i understood that part right. Air gap was close to being correct but now it is a snug .30

[redlowrey]

Do the test with the test light, that will tell me if the driver in the ecu is connecting the circuit to ground when it receives a crank signal, do the same on an injector remove a plug turn the key on should have power on gray wire with test light connected to ground, then swap the connections to battery pos , crank the engine and test the other pin light should blink.

If you disconnect the battery does the check engine light come on straight away when cranking after you hook it back up.

[redlowrey]

Can you give a bit of history on when the engine stopped

[redlowrey]

Were the plugs wet when you removed them.

[Wwarden5091]

Plugs were dry. Injectors work when i use actuater tests from SDS but using a mechanic stethiscope they only click during the rare occurance it tries to start. They are quiet during cranking. The engine ran fine the first of the season and sometimes would be hard to start when moving from one fishing hole to another. The boat is normally docked in the water all summer but i have it home now. The first time i had the no start condition i did not have any fault codes so i attacked the fuel system. Drained tank, drained dsv, replaced fuel lines, eliminated antisiphon valve. No eveidence of water from any of it. Put fresh fuel in tank, started right up, went fishing a couple days, ran fine. Came back to camp 2 weeks later no start, no run, no fault code. Pulled it from water looked over everything and decided to change CKP because it checked open with voltmeter. After i installed the new sensor from boats.net i started receiving 4-2 fault code. I get the code as soon as i turn my battery switch on and turn on key every time, before cranking.

[Wwarden5091]

so at that point i thought i had an intermittent ckp wiring issue so checked wiring from there to ecm with continuity and visual for any chaffing, sharp bends, etc. I may not get to do the test light tomorrow as we are expecting lots of rain and boat wont fit in garage but as soon as i can ill put a light on it

[Wwarden5091]

also changed low pressure and high pressure fuel filter while i was doing all the fuel work