Particulate Matter Sensor Protection Tube Performance Diagnostic May Set A False DTC P1488 Or P24DA (PIP5748F)
Reference number: PIP5748F
Supersedes refnos: PIP5748, PIP5748A, PIP5748B, PIP5748C, PIP5748D, PIP5748E
PARTICULATE MATTER SENSOR PROTECTION TUBE PERFORMANCE DIAGNOSTIC MAY SET A FALSE DTC P1488 OR P24DA
TECHNICAL SERVICE BULLETIN
SERVICE INFORMATION
| Brand: | Model: | Model Year: | VIN: | Engine: | Transmission: | ||
|---|---|---|---|---|---|---|---|
| from | to | from | to | ||||
| Cadillac | Escalade Models | 2021 | ALL | ALL | LM2 | All | |
| Chevrolet | Silverado | 2020-2021 | ALL | ALL | LM2 | All | |
| Chevrolet | Suburban | 2021 | ALL | ALL | LM2 | All | |
| Chevrolet | Tahoe | 2021 | ALL | ALL | LM2 | All | |
| GMC | Sierra | 2020-2021 | ALL | ALL | LM2 | All | |
| GMC | Yukon models | 2021 | ALL | ALL | LM2 | All | |
| Involved Region or Country | Canada Only |
| Condition | The Particulate Matter Sensor Protection Tube Performance diagnostic may falsely fail, causing DTC P1488 or P24DA to set and command the Malfunction Indicator Lamp (MIL) to illuminate. |
| Cause | This condition is currently under investigation by engineering. |
CORRECTION
If the vehicle has set DTC P1488 or P24DA, check to see if the particulate matter sensor is loose in the exhaust pipe. If so, this PI does not apply.
If the sensor is properly torqued and the P1488 or P24DA has requested the MIL, test the entire exhaust for leaks, and check for proper alignment of the tailpipe assembly to the under-floor SCR (this is a critical angle).
To test for leaks in the exhaust use the Power Smoke diagnostic leak detector (GE-52250 - refer to the latest version of PIP5684), but there are two important considerations. The smoke from the tester may not get through the DPF, so to test downstream of the DPF, administer the smoke downstream of the DPF.
Also, the tailpipe sealing bladder doesn't reach the exhaust cooler so use duct tape around the pipe to seal the cooler holes. Repair any leaks as necessary but pay particular attention to the joint illustrated in the pictures below.
If this joint is leaking the clamp may have bottomed out before applying sufficient clamp load to the joint, or damage may have occurred from mis-alignment of the joint. Also, misalignment of the joint may contribute to the P1488/P24DA setting, even if the joint does not leak.
Separate the joint and check the witness marks for proper alignment. If the joint was found to be leaking, also inspect for deformations to either half of the joint and replace the components as necessary. If the clamp was found to be bottomed out, replace the clamp.
Be certain to remove the duct tape from the exhaust cooler.
Also replace the particulate matter sensor.
This PI will be updated or replaced by a bulletin as additional information becomes available.
Please ensure you use the special labor operation for this concern.
These witness marks indicate proper alignment
These witness marks indicate improper alignment
PARTS INFORMATION
| Description | Part Number | Qty |
|---|---|---|
| Exhaust Clamp | 84283544 | 1 |
WARRANTY INFORMATION
For vehicles repaired under the Emissions (E, E2) coverage, use the following labor operation. Reference the Applicable Warranties section of Investigate Vehicle History (IVH) for coverage information.
| Labor Operation | Description | Labor Time |
|---|---|---|
| 4087528 | Exhaust Particulate Sensor Replacement | .4 Hours |
| ADD | Diagnostic Time (includes inspection) | 0 -.5 Hours |
| *This is a unique Labor Operation for Bulletin use only. | ||
| Version | 6 |
| Modified | 08/20/2020 - Created on. 09/25/2020 - Updated to include inspecting for an exhaust leak and add pictures. 10/20/2020 - Updated to modify the exhaust pipe sealing procedure. 11/18/2020 - Updated to provide exhaust alignment details 12/11/2020 - Updated to add models 01/08/2021 - Updated to add 2021 model year Silverado and Sierra 04/28/2021 - Updated to remove US but keep Canada |