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I have a swap using an 8.1 with an Allison trans From a 2002 Sierra. I cannot view anything to do with 5th gear or trans fluid temp. The editor only shows Shift tables for 1 thru 4, The scanner has no option to command 5th and I cannot see trans fluid temp. Wondering if this was an oversight during implementation? Anyone have any input?
are you able to post the .hpt file? I don't think we support the allison 5 speed in those applications, been a while since someone asked about these so off the top of my head I cannot remember exactly why.
Here u go Bill
Attachment 124121
Quote:
Originally Posted by Xbody
The 2002 Sierras with the 8.1L engine used a P01 PCM.
The P01 PCM was used to control both the engine and the transmission - except with the Allison transmission, which used its own separate controller (TCM).
The transmission portion of the P01 PCM calibration is still populated with data (by default) - but this data is not used to control the Allison transmission.
The tune that you posted is only the engine side (PCM) of the calibration.
I hear What your saying Shrek, But some of the "default" data seems specific to the 8.1. Trans Type> Allison; Torque management tables with values up to 600ftlbs; Desired Torque vs Engine speed = 600ftlbs; Shift Point RPMs are right as well. Then some weird Shit like the Trans gear Ratios are off. I have Seen the 8.1 with 6speed trans Tables and there are all 6 gears in the Tables. Maybe its the P01?
I will try to explain one more time .... all Allison transmissions use their own specific controller.
Your 2002 Sierra has a separate TCM to control the Allison transmission - disregard any transmission tables contained within the P01 PCM calibration.
If you look at a P01 PCM calibration from a manual transmission vehicle - the portion of the calibration for an automatic transmission is still populated - but is not in use.
If you wish to make changes to the Allison TCM tune - the first step is to actually read the TCM.
I do not know if HPT supports the 2002 Allison TCM. EFILive used to support this controller - but I have no idea if they still do.
I have read a 02 Silverado Duley years ago with a 8.1 and the 5 speed Allison and HP Tuners obviously read the Allison TCM because the Transmission tab is populated with what is obviously the Allison TCM data not the normal transmission data you would see with a 4L60 or 80. I didn't do anything special, just a normal read like I would with any other vehicle with a P01/auto. it even shows up in the Calibration data. Now when I would read these Allison vehicles with Tunercat it never read the separate TCM and what you would see in the transmission section would be like you described. And the file I have shows the shift tables for all 5 gears but nothing as far as trans temps.
To the OP, since you said it is a swap did you get the separate Allison TCM? It is usually mounted on the radiator core support
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Attachment 124144
I do have the controller installed and it all seems to function correctly. It looks like I'm not getting the TCM talking with the HP tuner interface.
This is all understood I appreciate your input.Quote:
Originally Posted by Shrek
What harness are you using for the swap. I will add that all I did was read the vehicle. I did not try to edit anything in the TCM. I never tried to use the scanner on it so I can't help with what PIDs are available for scanning.
Stock harness, pedal and all. there is a Class 2 data circuit that is yellow.. i think i need to investigate thatQuote:
Originally Posted by 2xLS1
1 BLK/WHT GROUND
2 PNK IGNITION 0
3 ORN B+
4 PNK IGNITION 0
5 BLK/WHT GROUND
6 YEL PTO REFERENCE VOLTAGE
7 PPL TCC BRAKE SWITCH / CRUISE CONTROL (K34)
8 –
9 WHT THROTTLE KICKDOWN SIGNAL (L18)
10 GRY/BLK 4WD LOW SIGNAL
11 –
12 –
13 –
14 –
15 –
16 TAN/BLK DELIVERED TORQUE SIGNAL (L18)
17 –
18 –
19 –
20 –
21 –
22 ORN/BLK REQUESTED TORQUE SIGNAL (L18)
23 –
24 –
25 DK BLU TRANS MIL REQUEST SIGNAL
26 –
27 YEL SIGNAL HIGH
28 –
29 YEL CAN SERIAL HIGH DATA
30 YEL TCM CLASS 2 SERIAL DATA
31 –
32 DK GRN CAN SERIAL DATA LOW