Retrieving DTCs with the ScanGauge

[CarlD]

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.

[mikelst]

Thank you for this information. I was able to verify my SERVICE SOON issue thanks to this.

Mike

[CarlD]

Interesting timing. Today I got a STOP SAFELY NOW message and attendant shutdown. After going through the modules, the ABS module returned a coded DTC of E023, or U2023.

Edit: corrected the DTC decoding

[CarlD]

And another ABS DTC today. SERVICE BRAKE SYSTEM in the message center and the ABS light on. The mode 0x18 request yielded 0x5175 which decodes to C1175, Wheel Speed Sensor LR Input Circuit Failure. Possibilities from the Shop Manual are opens/shorts, the wheel speed sensor or the ABS module. Hopefully not the ABS module......

[xcel]

Hi Carl:

___Are you going after codes the SG-II cannot resolve after a CEL or message appears?

___Secondly and more importantly, what was the outcome of the FEH’s ABS troubleshoot and repair?

___Good Luck

___Wayne

[CarlD]

Hi Wayne,

Yes, the mode 0x18 requests will retrieve the DTCs that the SCAN function won't. The only modules that seem to respond to the mode 0x03 requests are the PCM and TCM. There is a module at 07E2 that I think is the BCM OBD2 module, but it has never responded to a SCAN (mode 0x03) request. The battery, steering, ABS, 4WD and IC modules need the mode 0x18 requests to get their DTCs.

After going through the shop manual steps, nothing was found for the ABS DTC. Since I had one earlier for the ABS module, I suspect a loose connector or bad ground but I suppose it could be any random glitch or a decaying ABS module.

UPDATE: 12V battery failed this morning. After replacing it, more ABS module DTCs showed up. 5524 -> C1524 and 9318 -> B1318. C1524 is Brake Pedal Travel Sensor Calibration Incomplete; B1318 is Battery Voltage Low (duh!) At this point I am hoping the failing 12V battery was the cause of the DTCs because the ABS module lists for $4300 from Ford.

[CarlD]

Well, I now have a dead in the driveway FEH. STOP SAFELY NOW, the red triangle of death and the check engine light. Amazingly, the SCAN on the SG still shows no DTCs! However, using the mode $18 method above I was able to retrieve many DTCs from the PCM, TCM, ABS and TBCM computers. P0A0A was set in both the TCM and TBCM. After going through the diagnosis procedure in the PC/ED manual, the result is .... install new HV battery. Will have it towed to the dealer this week and see what they say. 94k on the odometer means it should still be in warranty for the battery.

Interesting in that both SOC and max charge power read ZERO despite the HV battery reading 340V.

[Right Lane Cruiser]

Well that's not fun.

I suspect (Warning!! Uninformed opinion imminent!) the zero readings are part of the software protections locking out use of the HV battery.

[GaryG]

Hi Carl

You may want to check those relays first because my '05 FEH PCM was reporting a bad HV battery also. You can just switch them around to check them because there all the same. Keep us informed at any rate.

GaryG

[CarlD]

Originally Posted by GaryG

Hi Carl

You may want to check those relays first because my '05 FEH PCM was reporting a bad HV battery also. You can just switch them around to check them because there all the same. Keep us informed at any rate.

GaryG

Good point about the relays. I forgot about those and that may be the problem. The failed 12V battery and all of the other DTCs that came and went recently could all just be symptoms of the $12 relays. I haven't had it towed in yet as I am out of town for three days.

For the diagnosis I followed the P0A0A HV Interlock steps in the diagnosis manual. This involved removing both the HV connector on the passenger side of the battery and the connector on the drivers side per the steps. The TCM HV interlock PID shows open and there is a 12V signal going into the HV battery on pin 14 but nothing coming out of the HV battery on the other connector. But hopefully all of this will be attributed to a failed relay. If it is I owe you a finder's fee since you had so much grief from Ford when it happened to you.