4.88's are IN!!
- Thread starter Psycho Mythic
- Start date
trussman
Active Member
Screw it. I will just tape my GPS over the speedo when the time comes. Problem solved.
Even with stock front wheels it was off. Perhaps the rear sensor is primary and it reverts to the front if it looses the signal from the rear?
VENOMOUS1 RACING
Has Left the Room - Banned from VTCOA!
Nah, fronts are for ABS speed signal only. 
505'sFastestViper.
Full Access Member
Dude I only had the front abs sensor in and the speedo still worked I'm not a fucking idiot.
505'sFastestViper.
Full Access Member
Disconnect the rear end tranny rear abs and your speedo will still work. Just because you washed cars at the dodge dealership doesn't make you an expert venomous
VENOMOUS1 RACING
Has Left the Room - Banned from VTCOA!
505'sFastestViper.
Full Access Member
Oops insert smilies
Psycho Mythic
Full Access Member
Yall some violent azz people at times, lawd
So fill us in: Do the sensors in the front send a signal to the speedo?That's all I do and I know what I'm talkiing about....I think
SergioL.
Full Access Member
Witch craft
The wiring diagram is very vague for the ABS system. All 3 sensors input to the ABS module, but it only shows a brake switch signal to the PCM. See attached picture. Unless I'm reading it wrong. :dontknow:
VENOMOUS1 RACING
Has Left the Room - Banned from VTCOA!
Ok, Dom is Correct and maybe Justin. Disconnected sensor and still had speedo:dontknow:
BUT.....it was obviously different as it took several mph from a stop to get going right. Did the same slowing down, so possibly reading fronts too?
BUT.....it was obviously different as it took several mph from a stop to get going right. Did the same slowing down, so possibly reading fronts too?
Based Andy's picture, the speedometer changes based on at least three different inputs.
VENOMOUS1 RACING
Has Left the Room - Banned from VTCOA!
The wiring diagram is very vague for the ABS system. All 3 sensors input to the ABS module, but it only shows a brake switch signal to the PCM. See attached picture. Unless I'm reading it wrong. :dontknow:
We need to see where the cluster gets its reading?
One moment please......
VENOMOUS1 RACING
Has Left the Room - Banned from VTCOA!
Never mind. Case closed!! It reverts to fronts as Arreztmered has said. No speedo with all 3 disconnected.
OPERATION
The speedometer gives an indication to the vehicle operator of the relative vehicle road speed. This gauge is controlled by the instrument cluster circuit board based upon cluster programming and electronic messages received by the cluster from the Powertrain Control Module (PCM) over the Programmable Communications Interface (PCI) data bus. The speedometer is an air core magnetic unit that receives battery current on the instrument cluster electronic circuit board through the fused ignition switch output (run-start) circuit whenever the ignition switch is in the On or Start positions. The cluster is programmed to move the gauge needle back to the low end of the scale after the ignition switch is turned to the Off position. The instrument cluster circuitry controls the gauge needle position and provides the following features:
Vehicle Speed Message - Each time the cluster receives a vehicle speed message from the PCM it will calculate the correct vehicle speed reading and position the gauge needle at that relative speed position on the gauge scale. The cluster will receive a new vehicle speed message and reposition the gauge pointer accordingly about every 88 milliseconds. The gauge needle will continue to be positioned at the actual vehicle speed position on the gauge scale until the ignition switch is turned to the Off position.
Communication Error - If the cluster fails to receive a speedometer message, it will hold the gauge needle at the last indication for a short delay period, or until the ignition switch is turned to the Off position, whichever occurs first. The delay is about three seconds for all diesel and gasoline engines except SRT-10, and about five seconds for SRT-10. After the appropriate delay, the cluster will move the gauge needle to the low end of the gauge scale.
Actuator Test - Each time the cluster is put through the actuator test, the speedometer needle will be swept to several calibration points on the gauge scale in a prescribed sequence in order to confirm the functionality of the gauge and the cluster control circuitry.
The PCM continually monitors the vehicle speed sensor or the Controller Anti-lock Brake (CAB) to determine the vehicle road speed. The PCM then sends the proper vehicle speed messages to the instrument cluster. For further diagnosis of the speedometer or the instrument cluster circuitry that controls the gauge, (Refer to 8 - ELECTRICAL/INSTRUMENT CLUSTER - DIAGNOSIS AND TESTING). For proper diagnosis of the vehicle speed sensor, the CAB, the PCM, the PCI data bus, or the electronic message inputs to the instrument cluster that control the speedometer, a DRBIII® scan tool is required. Refer to the appropriate diagnostic information.
The speedometer gives an indication to the vehicle operator of the relative vehicle road speed. This gauge is controlled by the instrument cluster circuit board based upon cluster programming and electronic messages received by the cluster from the Powertrain Control Module (PCM) over the Programmable Communications Interface (PCI) data bus. The speedometer is an air core magnetic unit that receives battery current on the instrument cluster electronic circuit board through the fused ignition switch output (run-start) circuit whenever the ignition switch is in the On or Start positions. The cluster is programmed to move the gauge needle back to the low end of the scale after the ignition switch is turned to the Off position. The instrument cluster circuitry controls the gauge needle position and provides the following features:
Vehicle Speed Message - Each time the cluster receives a vehicle speed message from the PCM it will calculate the correct vehicle speed reading and position the gauge needle at that relative speed position on the gauge scale. The cluster will receive a new vehicle speed message and reposition the gauge pointer accordingly about every 88 milliseconds. The gauge needle will continue to be positioned at the actual vehicle speed position on the gauge scale until the ignition switch is turned to the Off position.
Communication Error - If the cluster fails to receive a speedometer message, it will hold the gauge needle at the last indication for a short delay period, or until the ignition switch is turned to the Off position, whichever occurs first. The delay is about three seconds for all diesel and gasoline engines except SRT-10, and about five seconds for SRT-10. After the appropriate delay, the cluster will move the gauge needle to the low end of the gauge scale.
Actuator Test - Each time the cluster is put through the actuator test, the speedometer needle will be swept to several calibration points on the gauge scale in a prescribed sequence in order to confirm the functionality of the gauge and the cluster control circuitry.
The PCM continually monitors the vehicle speed sensor or the Controller Anti-lock Brake (CAB) to determine the vehicle road speed. The PCM then sends the proper vehicle speed messages to the instrument cluster. For further diagnosis of the speedometer or the instrument cluster circuitry that controls the gauge, (Refer to 8 - ELECTRICAL/INSTRUMENT CLUSTER - DIAGNOSIS AND TESTING). For proper diagnosis of the vehicle speed sensor, the CAB, the PCM, the PCI data bus, or the electronic message inputs to the instrument cluster that control the speedometer, a DRBIII® scan tool is required. Refer to the appropriate diagnostic information.
Never mind. Case closed!! It reverts to fronts as Arreztmered has said. No speedo with all 3 disconnected.
Correct! If it doesn't get a speed sensor reading it takes it from the ABS module, which gets its speed signal from all 3 sensors.
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