Farmall 70A - DTC 3157 (Resolved)

   / Farmall 70A - DTC 3157 (Resolved) #1  

klancf51

Silver Member
Joined
Jan 16, 2013
Messages
145
Location
PA
Tractor
CASE IH, Massey Ferguson, Ford
Farmall 70A no start – ADIC (Analog Digital Instrument Cluster) displayed “Stop Sign” icon and DTC 3157. Also, once, briefly displayed DTC 14901. The tractor had been sitting outside for about 10 days.

DTC 3157 - ECU Not Detected on CAN bus.
DTC 14901 – ECU not present

• We visually inspected the main wiring harness from the ECU back to the ADIC .
• We disconnected the wiring harness connectors from the ECU and re-connected them.
• We jump started the tractor successfully. After disconnecting the jumper cables, it ran for a few minutes and shut down with DTC 3157.
• We charged the battery. Again, it started and ran for a few minutes and shut down with DTC 3157.
• The next morning. we removed the battery, put it on the charger; meanwhile sprayed the grounding bolts in the battery compartment with brake cleaner and tightened them. Battery ground cable was not fully secure to frame and tightened ~ 1/8 turn. Re-installed the charged battery. Afterwards, tractor started and ran normally.

The reason we were suspicious of the battery and grounding is that for most ECU-related issues, the Farmall 70A Service Manual suggests “faulty supply voltage or ground, missing” as the #1 failure mode. The reason is that not all units on the CAN bus switch off communication at the same voltage level. This creates the situation where some components or control units are trying to communicate with switched-off units. Key takeaway: Always verify a properly charged battery and charging system as the first step in troubleshooting a CAN bus comms issue.

Btw, the DTC codes listed in the Farmall 70A Service Manual do not numerically correspond with those displayed on the ADIC. The Service Manual uses hexadecimal codes AND they don't convert directly to the DTCs on the ADIC. CASE IH should address this.

Hope this helps!
 
 
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