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Temperature Sensor

6K views 21 replies 7 participants last post by  tryNto 
#1 ·
Can anyone tell me if the outside temperature guage is connected to the ambient temperature sensor or some other sensor.
 
#7 ·
Should diagnose code for high voltage issue in circuit

Possible Causes

INLET AIR TEMPERATURE SENSOR, check resistance 300- 90 k ohms good sensor
(K69) SIGNAL CIRCUIT OPEN, should be less then 10 ohms to ECM
(Y502) RETURN CIRCUIT OPEN, should be less then 10 ohms to ECM
(K69) SIGNAL CIRCUIT SHORTED should be greater then 100 ohms checking other circuits on ecm connector

ECM connect jumper wire from k615(signal) and to k690(return) code P0072 should trip, if not ECM issue.
 
#14 ·
Ok. I’m not very mechanically blessed. But I have done a lot of reading. Truck will not crank when temp is around 30 degrees. I’ve had the truck in the shop already. Lift pump is new, replaced pressure relief valve, replaced banjo bolt in back of head. Cannot find air leak in return line. Truck acts as if it looses prime, but only when it’s cold. No smoke, and once running the truck it’s awesome. Only code I ever get is one about the fan clutch. But it comes and goes. Shop said injectors were good. Just wondering if a bad temp sensor could be my problem? Any help greatly appreciated
 
#15 ·
Plug truck in to block heater if it starts 99% chance injectors are issue.
Mechanic or you should check rail pressure when issue happens .
find better mechanic, BUY only NEW Bosch or BBI injectors to avoid issues
what fan code need to go thru diagnostics some can cause issue like your having.
Newbies guide here has FSM to help diagnose https://www.cumminsforum.com/forum/22069665-post1.html

Should post truck info for more pertinent help.:wink2:
 
#16 ·
Don’t have any way of checking rail pressure during crank. Once at idle edge shows it being about 6k. Truck will start better with block heater plugged in. He said the fuel return test ruled out injectors? What are other signs that bad injector would tip? Wouldn’t it smoke or run poorly? Also someone else mentioned the air getting in return ? What way could I find an air leak that’s not leaking fuel?
 
#18 ·
Fuel return test was probably done while warm. Not while cold.

The problem is when everything is cold. Once warmed up if it continues to start fine, it's almost definitely the injectors.
 
#20 ·
Also I found someone that would test each injector. I know truck has mileage on it ,And my injectors aren’t gonna be 100% Up to par. How do I know that they are causing the problems that I am having?what I don’t wanna do is spend all that $ on injectors and have new injectors and a truck that still won’t crank. Guess my question is... are injectors either good or bad. Or is there just a possibility of a weak injectior?
 
#22 ·
How many miles on your truck?
Are you confusing the term crank with start?
Crank/turn over but not start is your issue it seems.

Injectors can be weak/leaking/worn/good or bad.
Most every time a truck starting better when the block heater is plugged in means some or all of the injectors need to be replaced.
You can pull injectors and send them in to be tested.
Only a few places can properly test injectors.

Buy only NEW Bosch injectors or you can use BBI new or reman. Don't get reman from anywhere but BBI
 
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