No code Reader Function 2009 4500 CC

[Wiredawg]

My 2009 4500 set a code today as indicated by CEL. As soon as I got to work, I shut her down, turned the key on-off 3 times and no code displayed. Tried it again and again. I called my 5-Star and asked about ability to read codes on 2009 4500, and they said that capability was eliminated. Is this true?



So, I went to AutoZone, who read the code as U1421. When I started the truck (third time since code set), the CEL went out. I called the dealer back, and they told me the code is - Implausible Ignition Key Off Time Received. They told me to check the IO fuse was securely seated. Also they recommended I drop by to check it out on Friday. I'll see.



Wiredawg

 

[Bob4x4]

U1421-IMPLAUSIBLE IGNITION KEY OFF TIME RECEIVED







For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

This monitor checks if the timer that counts the ignition off time is stuck.



When Monitored:

Ignition on.



Set Condition:

If the difference between coolant temperatures at the previous ignition off and next key on is greater than -12. 2°C (10°F), and the ignition off time was less than two minutes, the Engine Control Module (ECM) increments a fail counter of one. If the fail counter reaches 16 counts, a DTC is set and MIL lamp turns on.





Possible Causes

CAN B OPEN OR SHORTED

CLUSTER MODULE

TOTALLY INTEGRATED POWER MODULE (TIPM)

ENGINE CONTROL MODULE (ECM)



Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure).







1. ACTIVE DTC





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NOTE: Low battery voltage as well or an IOD fuse which is missing or not pushed in completely can cause the DTC to set. Make sure that the battery is fully charged and Ignition Off Draw (IOD) fuse is properly installed before continuing.

1. Ignition on, engine not running.

2. With a scan tool clear DTCs.

3. Turn the ignition off.

4. Turn the ignition off.

5. With a scan tool read DTCs.





Is the DTC active at this time?



Yes



Go To 3



No



Perform the INTERMITTENT CONDITION diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure).







2. CHECKING THE ECM POWERS AND GROUNDS





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1. (Refer to 29 - Non-DTC Diagnostics/Drivability - Diesel - Diagnosis and Testing) and perform the CHECKING THE ECM POWERS AND GROUNDS diagnostic procedure.





Were any problems found?



Yes



Perform the appropriate repair.

Perform the POWERTRAIN VERIFICATION TEST - 6. 7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure).



No



Go To 3







3. CHECKING FOR TSB/ECM FLASH UPDATES





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1. Check for any Service Bulletins or ECM flash updates that may apply.





Were any Service Bulletins or ECM flash updates found?



Yes



Perform the appropriate repair.

Perform the POWERTRAIN VERIFICATION TEST - 6. 7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure).



No



Go To 4







4. CAN B BUS HARDWARE DTCs ALSO ACTIVE





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1. With a scan tool check for DTCs in the TIPM.





Are any CAN B Hardware related DTCs active at this time?



Yes



(Refer to 28 - DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Diagnosis and Testing) and perform the appropriate diagnostic procedure.



No



Replace and program the Engine Control Module in accordance with the Service Information.

Perform the POWERTRAIN VERIFICATION TEST - 6. 7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure).

 

[HBarlow]

Wiredawg,

If the CEL cleared itself it is probably nothing to worry about. Apparently the software diagnostics have fairly tight tolerances.

My truck set a CEL a year ago that stayed on for a week during a trip from TX to NC and return but ultimately cleared itself and never returned. The CEL and trouble code was based on an erroneous reading of fuel rail pressure.

I wonder if a service writer was simply throwing an answer derived from a rectal source at you to end the phone call. Perhaps that is correct but why? My '08 will read codes.

Let us know what you find out.

 

[Bob4x4]

The CEL will stay on for most DTC's while the code is active. The cel will go out for most codes after 4 good trips. Rationality codes are usually addressed by a tsb eventually if enough trucks trip the code

 

[MullenaxM]

Alot of the rationality codes I see are caused by low battery voltage. And most of the low battery voltage problems are caused by loose or corroded battery cables at the battery posts.



When the starter motor is engaged the intial amprage draw can be between 600 to 800 amps. And with loose or corroded battery cables the amprage draw can be boosted up to >900 amps. If the battery voltage drops below 9 volts momentarily on the intial engagement of the starter this code will set.



I would make sure the battery cables are clean and tight (If you can twist them with your hand they are not tight enough) and you might want to have your batteries tested for a possible dead cell.



Remember, the batteries have to be isolated from each other before they can be tested, If you test them with the battery cables connected to each other you are not getting a true test of each battery. It is possible for one battery to be good and the other battery to be bad.



Mike

 

[Wiredawg]

Mike,



Thanks, I'll check tomorrow. We packed everthing and moved out of our house this weekend, and my service manual CD got packed. I knew I should have kept it in the truck. Still want to checke out for sure whether the 2009 4500 dsiplays CEL codes. It did not following the tried and tru procedures of past years. I have an OBD II reader I will hook up to see if anything is stored and will let y'all know.



Wiredawg

 

[Ereynolds72]

Wiredawg,



I wonder if a service writer was simply throwing an answer derived from a rectal source at you to end the phone call.

I know I'm a little late to the party but that there is just funny. You do have a sense of humor Harvey.

 

[TulsaOkie]

Harvey has a way with words... .