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In allot of cases this takes several minutes of driving and key off and on switching to reset.There were some programming issues on the 2011 model that a GM dealer has to do to correct this issue as well as perform a DEF fluid quality test to reset it.Once the programming and test is done this will reset and should reset from there on out when you have to refill it without having to take it back into a dealer.Unfortunately though there was some programming issues that a dealer has to check and update with their computer.I know this usually takes an hour or less for them to do.Here is a copy of what the dealer has to do.
#PIP4864C: Low Or Speed Limited Diesel Exhaust Fluid Message Displayed Intermittently Or Will Not Reset - Including Cold Weather Operation - (Jan 13, 2011)
dealer may encounter a customer vehicle with a DEF (diesel exhaust fluid) low message, speed limiting message, or a DEF range not resetting after a refill. If the vehicle is known to be full of DEF, and the ambient temperature is less than -9 C or 16 F, the vehicle may enter a "Frozen Tank Status".
Frozen tank status is described at the bottom of the recommendation / instruction portion of this PI.
After a refill it may be necessary to drive the vehicle for a few miles before the DEF fluid information will update on the DIC. If the vehicle has been driven for a few miles, the ignition has been turned off (allowing the ECM to go to sleep for at least 5 minutes), and the DIC will not update, the message may have become latched into the ECM.
There are three different reasons for a DEF (Diesel Exhaust Fluid) warning message to set.
(Exhaust Fluid Empty Refill Now) A DEF tank fluid level warning - includes messages about adding fluid and exhaust fluid range
(Exhaust Fluid Quality Poor-see owner's manual now) A DEF Quality message - Makes sure DEF fluid is lowering NOx emissions to a satisfactory level (usually has DTC).
(Service Exhaust Fluid System-see owner's manual now) A DEF Fluid Tamper mode - Tamper mode is for conditions associated with an attempt to disable reductant system operation, or the system detects concerns (DTCs) with reductant system ope
It is important to know the exact DIC message so correct diagnostics are completed. Please see SI documents(###) ###-####(###) ###-#### and(###) ###-####for clarification.
Important: The tampering or quality messages must be resolved prior to performing this procedure. The procedure below has been set up to address DEF fluid level resets. For DEF system Quality or Tampering messages the newest version of PIP4829 should be completed.
Important: Any Engine DTCs must be diagnosed and repaired before the any DEF messages are addressed.
If all DTCs have been addressed, the DEF fluid tank level is showing full at 100%, and the vehicle has been driven for at least four to five miles (6.5 to 8.0 km) the dealer can reset ECM with the relearn procedure listed below.
Note: Be sure to complete this process on a level surface.
Drain the DEF tank following SI repair procedures-Fuel Tank Draining (Emission Reduction Fluid)
Use the Tech 2 to verify the tank has been completely drained. To verify the tank is completely empty all three Reductant Level Sensors (found in Tech 2 reductant system data) must show inactive. If a level sensor is sensing fluid it will show active.
The ECM will be reprogrammed using a "two part" level reset calibration available through TIS2WEB. This replaces the previous VCI calibration that required contacting GM Techline Customer Support Center. Part one of the two part calibration will be titled "ECM DEF tank fluid level warning latched reset programming per PIP4864". Select "Replace and Reprogram" as the Programming Process. Select "Normal" as the Programming Type.
Note: The vehicle will be speed limited to 5 mph (8 kph) if part one of the calibration is left in the ECM (If for some reason part two of the calibration is not installed). If the special DEF level reset selection is not found in TIS2WEB, please contact the GM Techline Customer Support Center (TCSC) at(###) ###-####(***-***-**** French) so the DEF level reset ECM programming option can be added.
Key off the ignition for at least 2 minutes (may be up to 5 minutes). The technician must be sure all retained power is dissipated completely when powering down the ECM.
Start the truck and allow to idle for one minute. During this time at least one of the following messages should be displayed on the DIC:
"Exhaust Fluid Empty Refill Now - 55 MPH (89 km/h) Max Speed Next Restart"
"Exhaust Fluid Empty Refill Now - Speed Limited to 55 MPH (89 km/h)",
"Exhaust Fluid Empty Refill Now - 4 MPH (6 km/h) Max Speed Next Fuel Fill",
"Exhaust Fluid Empty Refill Now - Speed Limited to 4 MPH (6 km/h)"
Shut down the truck and allow ECM to power down (ign. key off, wait 2 minutes).
With the ignition off fill the DEF tank with a maximum of 5 gallons (18.9 L).
Start the truck and allow the warning messages on the DIC to go away. When starting the vehicle it is important to move immediately from the Off position to the Start position. If the ignition is left in the Off position for a long period of time the refill detection will not occur. If this happens, turn the ignition off, wait two minutes, and then start the vehicle.
Turn off the vehicle and complete the ECM programming again with the second portion of the two part calibration titled "Engine Control Module" also available through TIS2WEB. This will update the vehicle to the current calibration in TIS2WEB - Select "Replace and Reprogram" as the Programming Process.
Important: If the correct calibration (second portion of two part calibration) is not reflashed into the vehicle it will be limited to 5 mph.
Note: THIS PROCEDURE MUST BE FOLLOWED EXACTLY; EVERY STEP MUST BE PERFORMED AS DETAILED.
Frozen Tank Status Description
In operating temperatures of -9C / 15F or less, customers may comment on an "Exhaust Fluid Range" message displaying on the DIC even though the DEF fluid has been filled or is known to be full. This is likely because the truck is in the "Frozen Tank Status". This is usually an intermittent condition.
If the DEF is frozen, the level sensor cannot determine the fluid level in the tank. If this occurs the logic of the PCM will assume a default fluid level. The logic will use the calculated range based on DEF dosing history and the assumed fluid level.
If there is a high learned dosing rate and the fluid has not thawed to where the pins of the level sensor can function, there is a possibility the "Exhaust Fluid Range" message can set with the range from approximately 1000 miles to less than 300 miles.
This is an operating characteristic of the system. However to increase or eliminate the range message, once the range drops below 300 miles, the DEF tank should be refilled. This should allow refill detection to occur and turn off the range indicator.
When in frozen tank status, refill detections are not allowed until the warning strategy reaches the point at which the distance remaining is less than 300 miles. The refill detection is dependent on the DEF thawing enough that the level sensor pins can be read. A fully frozen tank can take up to an hour to detect a refill after the vehicle is started and the DEF heaters are operating.
Related to the "Frozen Tank Status". When DEF is frozen, adding DEF may not be recognized until the fluid around the Discrete Level Sensors (DLS) has thawed. To verify if the fluid is frozen, the Tech 2 DEF level reading can be used. After a normal DEF tank fill, the DEF fluid level reading (on Tech 2) should have increased to 100%. If fluid was added and the level does not change, the DEF fluid may be frozen. The fluid will have to be thawed before completing the process in this PI. A reading of 100% does not indicate that the entire tank is thawed. As the DEF in the tank is thawing, it is normal to see the level sensors in the tank react differently than when the fluid is thawed. For example, pins 1 and 3 could be active and pin 2 inactive. This would not be possible with a thawed tank. When the range message is less than 300 miles, the refill detection should occur as soon as liquid DEF is contacting more than the first DEF fluid level pins.
Engineering is investigating the erratic DEF range messages. This PI will be updated when new information has been received.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
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