Is there some super here type person here that can decipher ECU codes?

What kind of truck..year make model, how many speeds

 

ECM SPN 84, Wheel-Based Vehicle Speed – MID 128 PID 84
Type of fault:
FMI Description:
Fault Condition:
Possible Symptoms:
Possible Cause:
FMI 9
• Abnormal update rate
• Missing signal from VECU
• Engine derate
• SAE J1587 data link vehicle speed message does not exist, (VECU error)
• VECU


I'm no expert but if it was intermittent then I would start looking at loose connectors at road speed sensor and also at vecu

Also, check these out
Examples of Common SAE J1708 Message Identification - MID
MID 128 Engine
MID 130 Transmission
MID 136 Brakes, Power Unit - ABS
MID 140 Instrument Cluster
MID 144 Cruise Control / Vehicle Control Unit
MID 146 Cab Climate Control
MID 150 Suspenstion, Power Unit
MID 166 Tires, Power Unit
MID 177 Particulate Trap System
MID 181 Communication Unit, Satellite
MID 200 Auxillary Cab Climate Control
MID 216 Light Control Administrator Unit
MID 232 Safety Restraint System
MID 249 Body Controller
Examples of Common SAE 1708 Parameter Identification - PID
PID 8 Brake system air pressure Low warning switch statuts
PID 12 Brake Stroke Status
PID 27 Percent Exhaust Gas Recirculation Valve #1 Postision
PID 51 Throttle Postion
PID 80 Washer Fluid Level
PID 81 Particulate Trap Inlet Pressure
PID 84 Road Speed
PID 91 Percent Accelerator Pedal Postition
PID 94 Fuel Delivery Pressure
PID 97 Water In Fuel Indicator
PID 98 Engine Oil Level
PID 100 Engine Oil Pressure
PID 101 Crankcase Pressure
PID 102 Boost Pressure
PID 103 Turbo Speed
PID 105 Intake Manifold Pressure
PID 106 Air Inlet Pressure
PID 107 Air Filter Differential Pressure
PID 108 Barometric Pressure
PID 109 Coolant Pressure
PID 110 Engine Coolant Temperature
PID 111 Coolant Level
PID 131 Exhaust Back Pressure
PID 153 Crankcase Pressure
PID 156 Injector Timing Rail Pressure
PID 157 Injector Metering Rail Pressure
PID 171 Ambient Air Temperature
PID 172 Air Inlet Temperature
PID 173 Exhaust Gas Temperature
PID 174 Fuel Temperature
PID 175 Engine Oil Temperature
Examples of Common SAE J1708 Subsystem Identification - SID
SID 213 PLC Data Link
SID 231 SAE J1939 Data Link
SID 232 5 Volts DC Supply
SID 250 SAE J1708/J1587 Data Link
SID 251 Power Supply
Examples of Common SAE J1708 Failure Mode Identifiers - FMI
FMI 0 Data Valid but above normal operational range
FMI 1 Data Valid but below normal operational range
FMI 2 Data Erratic
FMI 3 Voltage above normal - Shorted High
FMI 4 Voltage below normal - Shorted Low
FMI 5 Current below normal - Open Circuit
FMI 6 Current above normal - Grounded Circuit
FMI 7 Mechanical System Fault
FMI 8 Abnormal Frequency
FMI 9 Abnormal Update Rate
FMI 10 Abnormal Rate of Change
FMI 11 Failure Mode not Identified
FMI 12 Bad Device
FMI 13 Out of Calibration
FMI 14 Special Instructions

 

For some reason the vecu is not getting the right info. This is either due to a bad connection or bad vecu itself. Wish I could help more

 

have you added fuel additive? Cant explain the codes, but it sounds like iceing fuel to me. Do you have a new dpf truck? Some (petes) have ishues keeping fuel warm in filters. They couldn't replicate it at shop do to fuel warming in the shop. Thats my guess.

 

PID 84 is VSS signal

 

VSS sensor is on rear of transmission just behind yoke. About 40 bucks