has anybody in 4th Gen grounded their TB?
Record Breaker
Joined: Jan 2010
Posts: 1,400
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From: San Pedro, California
No ground used at all. There are 6 wires from the PCM C2 connector to the TB. There is a +5VDC Return for the +5VDC source used as the reference to the throttle position sensors, TPS1 and TPS2. The sensors are potentiometers (variable resistors with a wiper arm). As the throttle moves the wiper in the pots move and the voltage on the TPS1 and TPS2 change with the position (just like the fuel gauge indicator in the fuel tank). The PCM uses these TPS signals to know where the throtle is versus where it wants it to be. The throttle itself is moved by a motor that is controlled by the motor control+ signal and the motor control- signal. All of the electronics are referenced to the +5VDC Return, It's like the circuitry reference to all of the signals. If this wire was to break, then the circuit would not work.
PCM-C2-29 PK/YL wire is +5VDC to the sensors TB pin 2
PCM-C2-15 BR/DB wire is +5VDC Return to the sensors TB pin 6
PCM-C2-21 BR/OR wire is TPS1 to the PCM from TB pin 1
PCM-C2-28 BR/DG wire is TPS2 to the PCM from TB pin 4
PCM-C2-38 TN/OR wire is Motor(-) to theTB pin 5
PCM-C2-6 TN/YL wire is Motor(+) to theTB pin 3
PCM-C2-29 PK/YL wire is +5VDC to the sensors TB pin 2
PCM-C2-15 BR/DB wire is +5VDC Return to the sensors TB pin 6
PCM-C2-21 BR/OR wire is TPS1 to the PCM from TB pin 1
PCM-C2-28 BR/DG wire is TPS2 to the PCM from TB pin 4
PCM-C2-38 TN/OR wire is Motor(-) to theTB pin 5
PCM-C2-6 TN/YL wire is Motor(+) to theTB pin 3
Professional
Joined: Aug 2011
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From: Cumming, GA
2010 DS : 1500 RAM PICKUP
Mopar Package #05183469AA THROTTLE BODY - BLACK (ENGINE) 6 WAY
CAV CIRCUIT FUNCTION
TP 1 SIGNAL
5 VOLT SUPPLY
ETC MOTOR (+)
TP 2 SIGNAL
ETC MOTOR (-)
TP SENSOR RETURN
Mopar Package #05183469AA THROTTLE BODY - BLACK (ENGINE) 6 WAY
CAV CIRCUIT FUNCTION
A1
K22 20 BR/OR TP 1 SIGNAL
A2
F855 22 PK/YL 5 VOLT SUPPLY
A3
K447 20 TN/YL ETC MOTOR (+)
A4
K122 20 BR/DG TP 2 SIGNAL
A5
K448 20 TN/OR ETC MOTOR (-)
A6
K922 20 BR/DB TP SENSOR RETURN
A5 is the ground, right ? I suppose if this isn't sufficient, a "better" ground might improve operation of the throttle motor and give better response.
Record Breaker
Joined: Jan 2010
Posts: 1,400
Likes: 5
From: San Pedro, California
2010 DS : 1500 RAM PICKUP
Mopar Package #05183469AA THROTTLE BODY - BLACK (ENGINE) 6 WAY
CAV CIRCUIT FUNCTION
TP 1 SIGNAL
5 VOLT SUPPLY
ETC MOTOR (+)
TP 2 SIGNAL
ETC MOTOR (-)
TP SENSOR RETURN
Mopar Package #05183469AA THROTTLE BODY - BLACK (ENGINE) 6 WAY
CAV CIRCUIT FUNCTION
A1
K22 20 BR/OR TP 1 SIGNAL
A2
F855 22 PK/YL 5 VOLT SUPPLY
A3
K447 20 TN/YL ETC MOTOR (+)
A4
K122 20 BR/DG TP 2 SIGNAL
A5
K448 20 TN/OR ETC MOTOR (-)
A6
K922 20 BR/DB TP SENSOR RETURN
A5 is the ground, right ? I suppose if this isn't sufficient, a "better" ground might improve operation of the throttle motor and give better response.
The one signal that could be tied to ground without a problem is the TP sense Return (A6).
One more thing that is not shown in the circuit is if the motor body is grounded to the TB housing internally, it may be, but what good would that do if the housing is not connected to any conducting surface or ground. As I said earlier, it will not do any harm to ground the TB housing, but I wouldn't want to ground the ETC Motor (-) signal.
If I had an oscilloscope I could measure it and know right away - but I don't.
Last edited by Pedro Dog; Jan 30, 2012 at 07:43 PM.
Record Breaker
Joined: Jan 2010
Posts: 1,400
Likes: 5
From: San Pedro, California
I found a website that explains the basic functions of the TB and drive circuitry. It is from Clemson University Vehicular Electronics Lab. Her is the link:
http://www.cvel.clemson.edu/auto/sys...trol_demo.html
Since it's a typical control circuit, and in this case a GM circuit, it may be a little different but I doubt very much is it's much different than ours.
Electronic Throttle Body
The electronic throttle consists of a regular throttle body, a DC motor with gear transmission, and two potentiometers for sensing the throttle valve position. This module has a 6-pin interface, the definition of which is shown in Fig. 3. The DC motor is driven by a pulse-width-modulated (PWM) signal. The output voltage of the potentiometer is proportional to the throttle position. Two potentiometers are used to improve the accuracy and reliability of the system.
Drive Circuit
To operate the motor, a drive circuit is required. In this experiment, we used a transistor and a relay to form a simple drive circuit, which is shown in Fig. 5. The transistor operates in an on/off manner to generate the PWM drive signal (1 kHz). The duty cycle is controlled by the dSPACE processor to regulate the motor current (speed). A double-pole double-throw (DPDT) relay is used to change the rotation direction of the motor. The rated voltage and current of the DC power supply were set to 12 V and 1.6 A, respectively.
http://www.cvel.clemson.edu/auto/sys...trol_demo.html
Since it's a typical control circuit, and in this case a GM circuit, it may be a little different but I doubt very much is it's much different than ours.
Electronic Throttle Body
The electronic throttle consists of a regular throttle body, a DC motor with gear transmission, and two potentiometers for sensing the throttle valve position. This module has a 6-pin interface, the definition of which is shown in Fig. 3. The DC motor is driven by a pulse-width-modulated (PWM) signal. The output voltage of the potentiometer is proportional to the throttle position. Two potentiometers are used to improve the accuracy and reliability of the system.
Fig. 3. Pin definition of the electronic throttle.
Drive Circuit
To operate the motor, a drive circuit is required. In this experiment, we used a transistor and a relay to form a simple drive circuit, which is shown in Fig. 5. The transistor operates in an on/off manner to generate the PWM drive signal (1 kHz). The duty cycle is controlled by the dSPACE processor to regulate the motor current (speed). A double-pole double-throw (DPDT) relay is used to change the rotation direction of the motor. The rated voltage and current of the DC power supply were set to 12 V and 1.6 A, respectively.
Fig. 5. The drive circuit.
Last edited by Pedro Dog; Jan 30, 2012 at 10:09 PM.
