As some people have discovered, the scangauge will only find emissions-related DTCs set by the PCM or TCM when using the SCAN function. For the FEH, a common problem is the a/c blend door driver failure. This is a DTC of B1239 from the Traction Battery Control Module. There are other DTCs from the Power Steering Module and the ABS Module that don't register when using the SCAN function on the SG. The DTCs can be retrieved using xgauges, however. There are also non-emissions related DTCs from the PCM and TCM that won't show up with the SCAN function. First is an xgauge to retrieve the quantity of stored or pending codes for each module. It is coded as follows: TXD: 0745220200 RXF: 046205020600 RXD: 3008 MTH: 000100010000 NAM: SPC (or whatever you want) If this shows 0, you can step through the various modules to see if any others are reporting DTCs. Change the 0745 in the TXD to the following: 0720 - Instrument cluster 0730 - Power Steering Module 0745 - Traction Battery Control Module 0760 - ABS module 0761 - 4WD module If the BTC for the TBCM shows a non-zero number, then you retrieve the DTC with the following xgauge: TXD: 07451800FF00 RXF: 045810000000 RXD: 2810 MTH: 000100010000 NAM: DTC The DTCs will be coded per OBD-II specs. Again, for different modules change the first four digits of TXD to the number shown above for that module. If you get a non-zero display, the first digit can be decoded as follows: 0 - P0 1 - P1 2 - P2 3 - P3 4 - C0 5 - C1 6 - C2 7 - C3 8 - B0 9 - B1 A - B2 B - B3 C - U0 D - U1 E - U2 F - U3 So if you see 9239 displayed, the DTC is B1239. If two or more DTCs are present, the RXF changes to 055810000 and RXD changes to 3010 and you can only retrieve the first one and the first half of the second one. To clear DTCs, change TXD to 074514FF00 and RXF to 045410000000 and you should see a value changing between 7Fxx and 54yy.