Engine Controls and Fuel - 3.0L LM2 Diesel | Diagnostic Information and Procedures | Document ID: 5190538
Description
A Reductant System Tamper Warning Service Bay Test is required when the Service Emission
System message or Service Exhaust Fluid System message is displayed on the driver information
center (DIC). The Reductant System Tamper Warning Service Bay Test is used to verify proper
operation of the reductant system and clear the Diesel Exhaust Fluid Anti-Tampering Warning after
the condition causing the warning has been repaired.
Conditions for Running
The following conditions must be met in order to enable the scan tool Reductant System Tamper
Warning Service Bay Test:
No DTCs are set.
Battery voltage is greater than 11 V.
Vehicle speed is 0 km/h (MPH).
Engine coolant temperature (ECT) sensor is between 60-100°C (140-212°F).
Barometric pressure is greater than 70 kPa (10.2 PSI).
Ambient air temperature is greater than −30°C (−22°F).
Reductant temperature is greater than −20°C (−4°F) and not frozen.
Reductant level must be greater than 33 %.
Fuel temperature is less than 80°C (176°F).
SCR catalyst temperature is less than 300°C (572°F).
Brake pedal and accelerator pedal are in the released position.
Clutch pedal (if equipped) is in the released position.
Transmission is in Park or Neutral.
Diesel particulate filter (DPF) regeneration is not active.
Fuel tank is not empty.
Diagnostic Aids
The Reductant System Tamper Warning Service Bay Test will not be allowed or will be terminated
if any of the conditions listed below occur.
Reductant System Tamper Warning Service Bay Test Inhibit Reason
Corrective Action
Brake Pedal Applied
Verify the brake pedal was not applied during the Reductant System Tamper Warning Service Bay Test. If the pedal was not applied, test the brake pedal position sensor.
Clutch Pedal Applied
Verify the clutch pedal was not applied during the Reductant System Tamper Warning Service Bay Test. If the pedal was not applied, test the clutch pedal position sensor.
Reductant System Tamper Warning Service Bay Test Inhibit Reason
Corrective Action
APP
Verify the accelerator pedal was not applied during the Reductant System Tamper Warning Service Bay Test. If the pedal was not applied, test the accelerator pedal position sensor.
Transmission must be in Park or Neutral
Verify the transmission gear selector remained in Park or Neutral during the Reductant System Tamper Warning Service Bay Test. If the gear selector remained in Park or Neutral, test the transmission range switch and circuits.
Vehicle speed too high
Vehicle speed must be 0 km/h (0 MPH)
Battery Voltage Exceeds Limits
Battery voltage must be greater than 11 V
Engine Coolant Temperature Out of Range
Coolant temperature must be between 60– 100°C (140–212°F)
Incorrect Power Mode
Verify ignition is in Run position
Soot Accumulation Out of Range
Perform the Diesel Particulate Filter (DPF) Service Regeneration
Activation Timer Has Expired
Ensure engine and exhaust system are at operating temperature
Engine Speed Out of Range
Engine must be running
Exhaust Gas Temperature Out of Range
Exhaust system must be at operating temperature and engine must be operating properly
Diesel Particulate Filter Regeneration is Active
Diesel particulate filter must not be in regeneration mode
Fault Active
Repair the fault using the appropriate diagnostic procedure
Vehicle Speed Fault
Repair the fault using the appropriate diagnostic procedure
Transmission gear data is not valid
Check the transmission gear switch
Air Flow Out of Range
Check the engine induction system
Engine Position Information Invalid
Repair the fault using the appropriate diagnostic procedure
Reductant System Tamper Warning Service Bay Test Inhibit Reason
Corrective Action
Vehicle Speed DTC Present
Repair the fault using the appropriate diagnostic procedure
Reference Information
Description and Operation
Exhaust Aftertreatment System Description
Scan Tool Reference
Control Module References for scan tool information.
Reductant System Tamper Warning Service Bay Test
Verify DEF tank is full and not in reductant warning level restriction.
⇒ If the reductant system is in restriction
Fill the DEF tank and perform the scan tool Reductant Fluid Tank Level Reset procedure.
⇓ If the reductant system is not in restriction
Perform the Ambient Air Temperature Reset with a scan tool if the vehicle has been driven in
an outside temperature below −5°C (+23°F).
Engine idling and at operating temperature, observe the DTC information with a scan tool.
Verify there are no DTCs set.
⇒ If a DTC is set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle
⇓ If a DTC is not set
Disconnect scan tool.
Ignition Off for 2 minutes.
Ignition on.
Connect the scan tool and select the scan tool Reductant System Tamper Warning Service Bay
Test in the Output Controls menu and follow the instructions.
Command the Reductant System Tamper Warning Service Bay Test On with a scan tool. The
Reductant System Tamper Warning Service Bay Test should start and run for up to 20
minutes.
The Reductant System Tamper Warning Service Bay Test is complete when the Service
Emission System message or Service Exhaust System message turns Off.
⇒ If the DIC message does not clear
9.1. Command a second Reductant System Tamper Warning Service Bay Test On with a scan
tool.
⇒ If the DIC message does not clear after the second test, a condition with the system still
exists.
⇓ If the DIC message clears