Challenger 35, Challenger 45 and Challenger 55 Agricultural Tractors Electronic Systems Caterpillar

Illustration 1	g00565847
(1) Chassis Control Module (CCM). (2) Transmission F/R Solenoid Fuse (MDP-F20). (3) Transmission Oil Pressure Switch.

This fault code indicates the transmission oil pressure switch circuit has a lower than normal voltage and may be due to an open circuit, or a short to ground.

If F394, F392 and F388 occur at the same time, then the fuse MDP-F20 may be blown. Read the procedures for each of these fault codes before attempting repair.

Mode 3 may be used to aid in troubleshooting. P410 is the input parameter for the Transmission Oil Pressure switch. With the Key Start switch ON and the engine not running, P410 should be HI. If a short or an open circuit is present, P410 will indicate LO.

1. Visually inspect transmission oil pressure switch, Rear Main harness and connectors (C002, C003 and C182) for corrosion, damage or disconnected connectors.

   Expected Result: There is damaged parts or broken parts.

   • YES, clean, repair damage or reconnect connectors as appropriate. Check fault codes. If fault code is not active, repair is complete.

   • NO, go to Step 2.

2. With machine OFF, disconnect C182 from the transmission oil pressure switch. Check for open circuit across terminals of switch.

   Expected Result: There is an open in the circuit.

   • YES, replace Transmission Oil Pressure switch. Check fault code and if no longer active the repair is complete.

   • NO, go to Step 3.

3. With C182 disconnected, check for open circuit in Rear Main harness between C182-2 and C002-26. Also check between C182-1 and C003-K.

   Expected Result: There is an open in the circuit.

   • YES, locate and repair open circuit in Rear Main harness. Check fault code and if no longer active the repair is complete.

   • NO, go to Step 4.

4. With C182 disconnected, check for open circuit in Cab Main harness between MDP-F20 and C003-K. Also check MDP-F20 and MFP-3 fuses.

   Expected Result: There is an open in the circuit.

   • YES, locate and repair open circuit in Cab Main harness or replace fuses. Check fault code and if no longer active the repair is complete.

   • NO, go to Step 5.

5. Check for short circuit from C182-1 to chassis ground. Also check from C182-2 to chassis ground. Is there a short circuit?
   • YES, locate and repair short circuit in Rear Main harness or Cab Main harness. Check fault code and if no longer active the repair is complete.

   • NO, go to Step 6.

6. Download latest control module software into all control modules.

   Expected Result: The fault code is active.

   • YES, go to Step 7.

   • NO, repair is complete. Calibrate transmission and three-point hitch.

7. Replace the Chassis Control Module (CCM).

   Expected Result: The fault code is active.

   • YES, install the original CCM and repeat this troubleshooting procedure.

   • NO, go to Step 8.

8. Install the original CCM.

   Expected Result: The fault code is active.

   • YES, original CCM was faulty. Replace original CCM with new CCM. If fault code is not active, repair is complete. Download latest control module software into all modules. Calibrate transmission and three-point hitch.

   • NO, this fault code may have been caused by faulty connectors. Keep the original on the tractor. Clean all terminals on the CCM and reconnect. If fault code is not active, repair is complete. Download latest control module software into all modules. Calibrate transmission and three-point hitch.