Speedo/VSS Issue?
Speedo/VSS Issue - SOLVED! VDO Speedo works to ~20 MPH and then hangs. (Occasional jump to 30+ and then it falls back) Car accelerates to ~40 MPH and 3-4 shift seems to hang in neutral. (It appears that ECM is as confused as the speedo.)
Anyone else seen this kind of behavior? Figured that if the VSS sensor/circuit was broken I wouldn't get any Speedo output at all.
Thanks in advance!
'06 6.0L Escalade drivetrain (LQ9/4L65e) in a Jeep.
*** Solution ***
The problem was the reluctor wheel got loose on the output shaft. Sent pix to Advance Adapters and they said that I had been shipped the wrong reluctor. Looking at the inside, it was only touching on two points and worked loose.
New reluctor installed and all is well. Shifting properly, engaging OD/TCC.
Life is good!
Anyone else seen this kind of behavior? Figured that if the VSS sensor/circuit was broken I wouldn't get any Speedo output at all.
Thanks in advance!
'06 6.0L Escalade drivetrain (LQ9/4L65e) in a Jeep.
*** Solution ***
The problem was the reluctor wheel got loose on the output shaft. Sent pix to Advance Adapters and they said that I had been shipped the wrong reluctor. Looking at the inside, it was only touching on two points and worked loose.
New reluctor installed and all is well. Shifting properly, engaging OD/TCC.
Life is good!
Last edited by TomH; Aug 29, 2008 at 07:28 PM.
Is the VSS connected to the PCM & then a PCM signal to the speedo or is the VSS hooked directly to the speedo? In either case, sounds like the PPM (pulses per mile) that your VDO is looking for is different from what is being sent to it. That can explain the speedo. As to the shifting, if the VSS is connected to the PCM, then you can have a tuner look @ the program to correct the shifting problem. If the VSS is not connected to the PCM, it can also be corrected in the PCM through RPM settings &/or it may be a torque converter lock up issue. Need to know how the VSS is connected.
Thanks.
The VDO is getting its output from the PCM. It's programmed for 4K pulse/mile and was working correctly.
All-in-all, there is less than 100mi on the Jeep since the install, but this anomaly is something new that just cropped up in the past couple of days.
The whole powertrain has less than 200 miles on it. (It was a takeout from GM.)
My next move will be to un/replug the VSS and if that doesn't solve it, plan "B" is to pull and re-seat the VSS after validating the integrity of the reluctor.
The VDO is getting its output from the PCM. It's programmed for 4K pulse/mile and was working correctly.
All-in-all, there is less than 100mi on the Jeep since the install, but this anomaly is something new that just cropped up in the past couple of days.
The whole powertrain has less than 200 miles on it. (It was a takeout from GM.)
My next move will be to un/replug the VSS and if that doesn't solve it, plan "B" is to pull and re-seat the VSS after validating the integrity of the reluctor.
