OD Light Blinking, No Codes?
Thread Starter
|
Senior User
Joined: Jul 2015
Posts: 150
Likes: 0
OD Light Blinking, No Codes?
96 e150 351w E4OD
So the other day my OD light started blinking and 1st and 2nd started hard shifting at low rpm. At higher RPM is shifts relatively smooth.
So I pulled over and turned off the engine. Started the engine again and my tranny shifted the smoothest it has ever shifted for about 10 minutes and then OD light started blinking again with the hard shifting.
I plugged in my Scan Guage 2 and no codes are coming up. Do I need another device? I thought the tranny codes were stored in the PCM like everything else?
So the other day my OD light started blinking and 1st and 2nd started hard shifting at low rpm. At higher RPM is shifts relatively smooth.
So I pulled over and turned off the engine. Started the engine again and my tranny shifted the smoothest it has ever shifted for about 10 minutes and then OD light started blinking again with the hard shifting.
I plugged in my Scan Guage 2 and no codes are coming up. Do I need another device? I thought the tranny codes were stored in the PCM like everything else?
Cargo Master
Joined: Mar 2007
Posts: 2,935
Likes: 34
From: Arcadia, Fla
When the OD light flashes and trans hard shifts, does the speedometer show any jumping? Also if you have speed control(cruse) which works, does it hunt the set speed?
Most likely once you read the codes(OBD1) you will get a VSS problem code. This means the ECU is not getting correct speed information from the PSOM(speedometer ). This is a common issue now days as the PSOM(speedometer PCB) ages with bad connections and capacitors.
Before replacing the VSS sensor in rear axle(which everybody does first and problem is NOT fixed), do a search here for "hard shift transmission" in the 87 to 96 Pickup truck forum. There are many threads about this with diagnostic and repair info.
Most likely once you read the codes(OBD1) you will get a VSS problem code. This means the ECU is not getting correct speed information from the PSOM(speedometer ). This is a common issue now days as the PSOM(speedometer PCB) ages with bad connections and capacitors.
Before replacing the VSS sensor in rear axle(which everybody does first and problem is NOT fixed), do a search here for "hard shift transmission" in the 87 to 96 Pickup truck forum. There are many threads about this with diagnostic and repair info.
Thread
Thread Starter
Forum
Replies
Last Post
drembedded
1999 - 2003 7.3L Power Stroke Diesel
22
Aug 17, 2011 09:43 AM
Highmark18
Pre-Power Stroke Diesel (7.3L IDI & 6.9L)
10
Jul 16, 2005 11:10 PM
