Would someone tell me what the codes mean? I got these codes when my truck engine was shutoff and the key was on? 54,21,16,32,75,42.... I have been having this problem with my truck not wanting to start after it warms up a bit??? What one of these codes would cause this problem?

 

16 - IDM signal not received
this is ignition related - the computer uses this circuit to monitor the function of the ignition coil. Track this one down, it could be one of the reasons the truck won't start.

21 - ECT out of test range.
Was the engine warm during the test? This code will come up if the engine is not warm when you run the test. However if it was warm, then there's a problem in the engine temperature sensor system, either the wiring or the sensor itself. Usually coolant temp sensors don't go bad. If the truck is warm and it still shows this code, then that might be a reason for not starting, in addition to some other things too.

32 - EGR valve opening not detected
the valve position sensor is registering too little voltage for what the computer expects to see. Could be a defective EGR valve, EVR solonoid, the valve could be stuck, etc. It will take some troubleshooting to narrow down the problem. This shouldn't be what is keeping the truck from running.

42 - O2 sensor rich, switching not detected
Sounds like the engine is running rich, and the computer can't lean out the mixture enough. This could be due to other problems, so don't replace the O2 sensor just yet.

54 - air temp sensor voltage above maximum
again, this could be due to running the test with the engine not warmed up, so I wouldn't put too much in this code.

75 - BOO (brake on - off switch) failure, always on
This shouldn't have come up in the engine off test.

 

Hey man, how can I contact you? I would love to talk to you man???

 

Code 75 is only produced during a KOER test, yet you said the truck wasn't running. This one is inconsistant. You can get code 75 during the KOER test if you run the test with your foot on the brake the whole time.

Code 54 typically means the ACT circuit is open -- the voltage is way, way too high. Code 24 means the engine isn't warmed up yet.

I have to wonder if this is codes 542, 116, 327. I know from personal experience that it can be easy to confuse three digit codes with two digit codes.

Report exactly the pattern of flashes and pauses that you see, including the separator pulse.

 

I was also wondering if it was 3 digit codes. What year is your truck? these could be KOEO codes or continous codes or both depending on the order in which they flashed.

 

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