John Deere 2850.06 – JDLink / Modular Telematics Gateway (MTG) or Custom Radio Unit (CRU): Cellular Antenna Error - Grounded/Short Circuit

High current detected in radio antenna circuit, which almost always points to a short-to-ground condition in the antenna circuit.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6R series
• 7R series
• 8R series
• 9R series
• 250D
• 300D
• 350D
• 400D
• 540G-III
• 548G-III
• 640
• 648G-III
• 460D
• E240LC
• 7180
• 7280
• 7380
• 7480
• 7580
• 7780
• 7980

1. 1

   Safety First: Disconnect battery power before servicing the MTG/Radio to avoid exposure to high radio frequency fields and prevent further electrical damage.

2. 2

   Visual Inspection: Trace the cellular/radio antenna cable from the MTG/CRU to the cab roof. Look for pinched wires, chafing against the cab frame, or exposed copper that could cause a short to the machine's chassis (ground).

3. 3

   Connection Check: Inspect the coaxial connections at the back of the MTG/CRU and at the antenna base. Look for moisture intrusion, corrosion, or bent pins.

4. 4

   Isolate the Short: Disconnect the antenna cable from the module and use a digital multimeter to test for continuity to ground. Disconnect the antenna from the cable to determine if the short is in the wiring harness or internal to the antenna base itself.

1. 1

   Power Down

   Turn off the machine and disconnect the battery.

2. 2

   Access the Module

   Locate the MTG or CRU. Depending on the machine, this is typically found in the cab roof liner or behind the right-hand storage box/trim panels (e.g., C-pillar).

3. 3

   Remove Faulty Component

   If the cable is shorted, carefully unroute the damaged coaxial cable. If the antenna is internally shorted, unbolt the antenna base from the exterior of the cab roof.

4. 4

   Install New Parts

   Mount the replacement antenna to the roof and/or route the new antenna cable. Ensure the cable is secured with zip-ties or grommets away from sharp metal edges to prevent future chafing.

5. 5

   Reconnect

   Plug the antenna cable securely into the MTG/CRU port.

6. 6

   Verify

   Reconnect the battery, turn the key to the ON position, and allow the JDLink/Radio system to boot. Clear the diagnostic trouble codes via the CommandCenter or Service ADVISOR and verify that 002850.06 does not return.