* P1623 - Transmission Temp Pull-Up Resistor
* P1624 - Customer Snapshot Requested - Data Available
* P1625 - TCM System Reset
* P1626 - Theft Deterrent Fuel Enable Signal Not Received
* P1627 - A/D Performance
* P1628 - ECT Pull-Up Resistor
* P1629 - Theft Deterrent System - Cranking Signal
* P1630 - Theft Deterrent Learn Mode Active
* P1631 - Theft Deterrent Start Enable Signal Not Correct
* P1632 - Theft Deterrent Fuel Disable Signal Received
* P1633 - Ignition 0 Switch Circuit
* P1634 - Ignition 1 Switch Circuit
* P1635 - 5 Volt Reference Circuit
* P1636 - PCM Stack Overrun
* P1637 - Generator L-Terminal Circuit
* P1638 - Generator F-Terminal Circuit
* P1639 - 5 Volt Reference 2 Circuit
* P1640 - Driver-1-Input High Voltage
* P1641 - Malfunction Indicator Lamp (MIL) Control Circuit
* P1642 - Vehicle Speed Output Circuit
* P1643 - Engine Speed Output Circuit
* P1644 - Traction Control Delivered Torque Output Circuit
* P1645 - Evaporative Emission (EVAP) Vent Solenoid Contorl Circuit
* P1646 - Evaporative Emission (EVAP) Vent Solenoid Control Circuit
* P1647 - Driver 1 Line 7
* P1650 - Control Module Output B Circuit
* P1651 - Fan 1 Relay Control Circuit
* P1652 - Powertrain Induced Chassis Pitch Output Circuit
* P1653 - Oil Level Lamp Control Circuit
* P1654 - Cruise Control Inhibit Output Circuit
* P1655 - EVAP Purge Solenoid Control Circuit
* P1656 - Driver 2 Line 6
* P1657 - 1-4 Upshift Solenoid Control Circuit
* P1658 - Starter Enable Relay Control Circuit
* P1660 - Cooling Fan Control Circuits
* P1661 - MIL Control Circuit
* P1662 - Cruise Lamp Control Circuit
* P1663 - Oil Life Lamp Control Circuit
* P1664 - 1-4 Upshift Lamp Control Circuit
* P1665 - Driver 3 Line 5
* P1666 - Driver 3 Line 6
* P1667 - Reverse Inhibit Solenoid Control Circuit
* P1669 - ABS Unit Expected
* P1670 - Driver 4
* P1671 - Driver 4 Line 1
* P1672 - Low Engine Oil Level Lamp Control Circuit
* P1673 - Engine Hot Lamp Control Circuit
* P1674 - Tachometer Control Circuit
* P1675 - EVAP Vent Solenoid Control Circuit
* P1676 - Driver 4 Line 6
* P1677 - Driver 4 Line 7
* P1680 - Driver 5 (ECU Malfunction)
* P1681 - Driver 5 Line 1
* P1682 - Driver 5 Line 2
* P1683 - Driver 5 Line 3
* P1684 - Driver 5 Line 4
* P1685 - Driver 5 Line 5
* P1686 - Driver 5 Line 6
* P1687 - Driver 5 Line 7
* P1689 - Delivered Torque Circuit Fault
* P1690 - ECM Loop Overrun
* P1691 - Coolant Gage Circuit Low Voltage
* P1692 - Coolant Gage Circuit High Voltage
* P1693 - Tachometer Circuit Low Voltage
* P1694 - Tachometer Circuit High Voltage
* P1695 - Remote Keyless Entry Circuit Low
* P1696 - Remote Keyless Entry Voltage High
* P1700 - Transmission Control Module (TCM) Requested MIL Illumination
* P1701 - Trans. MIL Request Circuit
* P1705 - P/N Signal Output Circuit
* P1719 - Incorrect Shifting Detected (TCM)
* P1740 - Torque Reduction Signal Circuit
* P1743 - TP Signal from ECM
* P1760 - TCM Supply Voltage Interrupted
* P1779 - Engine Torque Delivered to TCM Signal
* P1780 - Park/Neutral Position [PNP] Switch Circuit
* P1781 - Engine Torque Signal Circuit
* P1790 - Transmission Control Module Checksum
* P1791 - Transmission Control Module Loop
* P1791 - Throttle/Pedal Position Signal (2000+)
* P1792 - Transmission Control Module Reprogrammable Memory
* P1792 - ECM to TCM Engine Coolant Signal
* P1793 - Transmission Control Module Stack Overrun
* P1793 - Wheel Speed Signal (2000+)
* P1795 - CAN Bus - Throttle Body Position
* P1800 - TCM Power Relay Control Circuit
* P1801 - Performance Selector Switch Failure
* P1804 - Ground Control Relay
* P1810 - TFP Valve Position Switch Circuit
* P1811 - Maximum Adapt and Long Shift

 

* P1812 - Transmission Over Temperature Condition
* P1813 - Torque Control
* P1814 - Torque Converter Overstressed
* P1815 - Transmission Range Switch - Start In Wrong Range
* P1816 - TFP Valve Position Sw. - Park/Neu. With Drive Ratio
* P1817 - TFP Valve Position Sw. - Reverse With Drive Ratio
* P1818 - TFP Valve Position Sw. - Drive Without Drive Ratio
* P1819 - Internal Mode Switch - No Start\Wrong Range
* P1820 - Internal Mode Switch Circuit A Low
* P1822 - Internal Mode Switch Circuit B High
* P1823 - Internal Mode Switch Circuit P Low
* P1825 - Internal Mode Switch - Invalid Range
* P1826 - Internal Mode Switch Circuit C - High
* P1831 - Pressure Control (PC) Solenoid Power Circuit - Low Voltage
* P1832 - Pressure Control (PC)/Shift Lock Solenoid Control Circuit High Voltage
* P1833 - A/T Solenoids Power Circuit - Low Voltage
* P1834 - Torque Converter Clutch (TCC)/Shift Solenoid (SS) Control Circuit High Voltage
* P1835 - Kick-Down Switch Circuit
* P1836 - Kick-Down Switch Failed Open
* P1837 - Kick-Down Switch Failed Short
* P1842 - 1-2 Shift Solenoid Circuit Low Voltage
* P1843 - 1-2 Shift Solenoid Circuit High Voltage
* P1844 - Torque Reduction Signal Circuit Desired By TCM
* P1845 - 2-3 Shift Solenoid Circuit Low Voltage
* P1847 - 2-3 Shift Solenoid Circuit High Voltage
* P1850 - Brake Band Apply Solenoid Circuit
* P1851 - Brake Band Apply Solenoid Performance
* P1852 - Brake Band Apply SolenoidLow Voltage
* P1853 - Brake Band Apply Solenoid High Voltage
* P1860 - TCC PWM Solenoid Circuit Electrical
* P1864 - Torque Converter Clutch Circuit
* P1865 - 4-5 Shift Solenoid (SS) Valve Control Circuit High Voltage
* P1866 - Torque Converter Clutch (TCC) Pulse Width Modulation (PWM) Solenoid Control Circuit Low Voltage
* P1867 - Torque Converter Clutch (TCC) Pulse Width Modulation (PWM) Solenoid Control Circuit High Voltage
* P1868 - Transmission Fluid Life
* P1870 - Transmission Component Slipping
* P1871 - Undefined Gear Ratio
* P1873 - TCC Stator Temp. Switch Circuit Low
* P1874 - TCC Stator Temp. Switch Circuit High
* P1875 - 4WD Low Switch Circuit Electrical
* P1884 - TCC Enable/Shift Light Circuit
* P1886 - Shift Timing Solenoid
* P1887 - TCC Release Switch Circuit
* P1890 - ECM Data Input Circuit
* P1890 - Throttle Position Signal Input
* P1891 - Throttle Position Sensor PWM Signal Low
* P1892 - Throttle Position Sensor PWM Signal High
* P1893 - Engine Torque Signal Low Voltage
* P1894 - Engine Torque Signal High Voltage
* P1895 - TCM to ECM Torque Reduction Circuit
* P2008 - Intake Manifold Runner Control (IMRC) Solenoid Control Circuit
* P2009 - Intake Manifold Runner Control (IMRC) Solenoid Control Circuit Low Voltage
* P2010 - Intake Manifold Runner Control (IMRC) Solenoid Control Circuit High Voltage
* P2066 - Fuel Level Sensor 2 Performance
* P2067 - Fuel Level Sensor 2 Circuit Low Voltage
* P2068 - Fuel Level Sensor 2 Circuit High Voltage
* P2096 - Post Catalyst Fuel Trim System Low Limit
* P2097 - Post Catalyst Fuel Trim System High Limit
* P2098 - Post Catalyst Fuel Trim System Low Limit
* P2099 - Post Catalyst Fuel Trim System High Limit
* P2100 - Throttle Actuator Control (TAC) Motor Control Circuit
* P2101 - Control Module Throttle Actuator Position Performance
* P2105 - Throttle Actuator Control (TAC) System - Forced Engine Shutdown
* P2107 - Throttle Actuator Control (TAC) Module Internal Circuit
* P2108 - Throttle Actuator Control (TAC) Module Performance
* P2119 - Throttle Closed Position Performance
* P2120 - Accelerator Pedal Position (APP) Sensor 1 Circuit
* P2121 - Accelerator Pedal Position (APP) Sensor 1 Performance
* P2122 - Accelerator Pedal Position (APP) Sensor 1 Circuit Low Voltage
* P2123 - Accelerator Pedal Position (APP) Sensor 1 Circuit High Voltage
* P2125 - Accelerator Pedal Position (APP) Sensor 2 Circuit
* P2127 - Accelerator Pedal Position (APP) Sensor 2 Circuit Low Voltage
* P2128 - Accelerator Pedal Position (APP) Sensor 2 Circuit High Voltage
* P2135 - Throttle Position (TP) Sensor 1-2 Correlation
* P2138 - Accelerator Pedal Position (APP) Sensor 1-2 Correlation
* P2176 - Minimum Throttle Position Not Learned
* P2500 - Generator L-Terminal Circuit Low Voltage
* P2501 - Generator L-Terminal Circuit High Voltage
* P2535 - Ignition 1 Switch Circuit High Voltage (PCM)
* P2610 - ECU Malfunction
* P2763 - Short to voltage in the TCC Solenoid
* P2764 - Open or Short to ground in the TCC PWM solenoid valve circuit
* P2A00 - HO2S Circuit Closed Loop (CL) Performance Bank 1 Sensor 1 (PCM)
* P2A01 - HO2S Circuit Closed Loop (CL) Performance Bank 1 Sensor 2 (PCM)
* P3000 - Hacking AWH Data

 

First the best idea instead of listening to me is to take the car to and experienced tuner and let them do what they do. IMO

However since I get many calls about certain things, Here are a few things you should always do.

1-turn off the test for the codes po751 and po757 this will help avoid the limp mod after stall up or driving with a high stall converter.

2-Set lockup to happen only in 4th gear and above 40 mph .IMO

3-Set lockup so it cuts out under throttle way before the trans does a down shift. A down shift with lockup on can break hard parts in particular the input drum and shaft.

4-set the TCC duty cycle min and max at there highest setting though with our unit this would serve no purpose since we have mechanically set it to always be max. In any case this will help to prolong the life of the lockup clutch by reducing slipping.

5-Always with a built trans ours for sure set the line pressure tables at stock. Using tuning to raise line IMO is not the right way to get a firmer shift and has little or no affect on WOT shifts anyway.

6-shift points can be set wherever you like however remember that there is a delay mechanically from command to shift and this will vary with transmission condition, I have found from talking with customers that allowing 200 rpm for the 1-2 and 300 rpm for the 2-3 seems to work out in most cases. However the more power you make the more room you may need as the time for the trans to make the shift is a constant but as power increases the RPM rise is faster so more time is required. EXAMPLE" N/A verses SPRAYED.
For instance where it might take 200 rpm to make the shift N/A it might take 300 with a 150 shot. Also remember that RPM cannot be used as a stand alone to set shift points MPH comes into play also and additionally the KICK DOWN - speeds and throttle percentage also come into play I am told and affect the WOT up shift as well.

Now bear in mind I am not a tuner and these are actually things I have learned from actual tuners and customers doing there own tuning after solving different issues.
I do however have a copy of EFI LIVE I keep on my computer so I can at least us it to try and understand what I am told and read.
__________________

 

Found this on another forum posted as a single thread but wanted to have in this thread for easy reference also

PO121 CODE OR QUICK SHIFT 1-2-3-4 at WOT by 40 MPH FIX
Found this info on another forum and I know many people have popped up with this issue and wanted a fix. This would appear to be it. Hope it helps someone.

The curse of the P0121 Code... This code is infamous for giving people with larger cams fits...everything from traction control troubles, to shift point issues to just the good ole' P0121 code showing up for seemingly no reason making people scramble to purchase new Throttle Position sensors, adjust their set screws, etc, etc.

Before I go any further have a gander at the DTC information provided by LS2.com

http://www.ls2.com/boggs/dtcs/DTC%20P0121.htm

To outline a few key points

Quote:
The MAP is greater than 65 kPa

Quote:
The predicted throttle angle does not match the actual throttle angle

Quote:
All conditions present for 20 seconds

Now, that 65kpa map figure comes into play in nearly every LS1 Car/Truck because its the max map setting in most of the calibrations for the sanity test as shown here


Under normal circumbstances a stock cammed A4 will probably idle at around 35-40 map. When switching to a larger cam with more overlap your map readings could go up to as high as 70 or more kpa map which is way outside of the normal boundries. On a stock cammed car you'd probably need to be at around 30% tps to hit that same map number which is where that predicted throttle angle quote comes into play.

Now onto the last quote the 20 second timeframe. This will Usually come into play more often than not at idle with large cammed vehicles because many times your steady state map will be within the map sanity guidelines so there is a good possibity you might not see this code pop up immediatly.

There are a few ways you can cure this issue
a. Do as suggested in the help file which is to just set the min to 0 & max to 100
b. Adjust them to YOUR liking so you'll be within a reasonable limit. This will help determine if there IS a real issue with your TPS sensor later down the line.

So there you have it, as good an explanation I can come up with for that bastard code. So the next time you go WOT in your auto LS1 with a large cam & you go from 1st to 4th by 40mph or just a nagging p0121 code for no obvious reason you now have the info needed to fend it off.

 

13
Oxygen sensor circuit wiring/connection
55
Lean fuel monitor
14
Coolant sensor high temp. indicated
58
Trans Fluid high temp. indicated
15
Coolant sensor low temp. indicated
59
Trans Fluid low temp. indicated
16
Ignition low resolution pulse not detected
61
Low R134A pressure indicated
21
TPS signal voltage high -REPLACE TPS MAKE SURE PLUGGED IN (THROTTLE POSITION SENSOR)
63
Right heated O2 sensor lean indicated
22
TPS signal voltage low-REPLACE TPS (THROTTLE POSITION SENSOR)
64
Right bank O2 sensor lean indicated
23
IAT sensor low temp. indicated
65
Right bank O2 sensor rich indicated
24
VSS fault, no pulse indicated-REPLACE VSS (VEHICLE SPEED SENSOR)
66
A/C pressure sensor low pressure
25
IAT sensor high temp. indicated.
67
A/C pressure sensor circuit fault
26
EVAP purge control solenoid circuit.
27
EGR vacuum solenoid circuit
68
A/C relay fault
28
Transmission range control circuit-REPLACE MPS SENSOR IN TRANS (MANIFOLD PRESSURE SENSOR)
69
A/C relay fault
29
Secondary air injection circuit
70
A/C high pressure indicated
32
EGR failure
71
A/C evap sensor low temp indicated
33
MAP sensor signal high
72
VSS signal circuit error
34
MAP sensor signal low
73
Trans. pressure solenoid current surge-REPLACE PCS (PRESSURE CONTROL SOLENOID)
36
Ignition faulty high resolution signal
74
Traction control system
37
TCC brake switch stuck ON-CHECK BRAKE SWITCH UNDER DASH
75
Transmission system low voltage-CHECK ALTERNATOR OUT PUT AND BATTERY CONNECTIONS
38
TCC brake switch stuck OFF-CHECK BRAKE SWITCH UNDER DASH
77
Cooling fan relay control
39
Clutch switch error
79
Trans. temp sensor high temp. indicated
41
No ignition control circuit
80
Trans. component harness fault-CHECK THAT HARNESS PLUGGED INTO TRANS AND NO PINCHED OR BROKEN WIRES
42
Ignition control module circuit
81
Trans 2-3 shift solenoid circuit-REPLACE 2-3 SHIFT SOLENOID
43
Knock sensor wiring open or shorted
82
Trans 1-2 shift solenoid circuit-REPLACE THE 2-3 SHIFT SOLENOID
44
Lean exhaust detected
83
reverse switch inhibit circuit
45
Rich exhaust detected
84
Skip shift or 3-2 shift solenoid circuit-REPLACE THE 3-2 SHIFT SOLENOID
46
VATS pass key circuit fault
85
TCC stuck ON-REPLACE THE TCC SOLENOID AND CHECK VALVE ABOVE IT (TORQUE CONVERTER CLUTCH SOLENOID)

47
Knock sensor module or circuit
90
TCC solenoid circuit fault-REPLACE TCC SOLENOID
91
Skip shift lamp circuit
48
MAF sensor circuit
97
VSS output signal voltage low-REPLACE THE VSS (VEHICLE SPEED SENSOR)
50
System voltage low
99
TACH output circuit
51
PROM/EEPROM error


53
System voltage high-CHECK ALTERNATOR OUTPUT VOLTAGE