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

Illustration 1	g00562250
(1) Chassis Control Module. (2) Speed Sensor (Transmission). (3) Speed Sensor (Engine).

This fault code indicates the engine RPM sensor has a lower than normal voltage and may be due to a shorted sensor or a harness short to chassis ground.

1. Inspect engine RPM sensor connector (C160) to determine whether the sensor, connectors or Rear Main harness is damaged.

   Expected Result: There is a damaged harness. The sensor is corroded. A connector is separated.

   • YES, repair as appropriate and recheck fault codes. If fault code is not active, repair is complete.

   • NO, go to Step 2.

2. Disconnect engine RPM sensor and measure the resistance across terminals 1 and 2. The resistance should be 2550 ohms.

   Expected Result: There is a short circuit.

   • YES, replace engine RPM sensor. Check fault code and if no longer active the repair is complete.

   • NO, go to Step 3.

3. If the transmission speed sensor is functioning properly, exchange the transmission speed and engine RPM sensors. Check fault codes.

   Expected Result: The fault code is not active.

   • YES, install new engine RPM sensor. Check fault code and if no longer active the repair is complete.

   • NO, go to Step 4.

4. Disconnect Chassis Control Module connector C002. Check for short circuit between C160-1 and C160-2.

   Expected Result: There is a short circuit.

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 Check fault code and if no longer active the repair is complete.

   • NO, go to Step 5.

5. Check for short circuit from chassis ground to C160-1 and C160-2.

   Expected Result: There is a short circuit.

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 Check fault code and if no longer active the repair is complete.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