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

Illustration 1	g00564743
(1) Chassis Control Module (CCM). (2) Air filter vacuum switch. (3) Engine oil pressure sensor. (4) Rockshaft potentiometer.

Illustration 2	g00578350
Location of connectors.

This fault code indicates the CCM sensor 5 volt supply circuit has a lower than normal voltage (less than 4.0 volts). This may be due to a short to ground or open circuit.

1. Inspect wiring harness, connectors, rockshaft potentiometer, engine oil pressure sensor and air filter vacuum switch for damage such as bare wires, shorted, or crushed wiring.

   Expected Result: There is damaged parts or broken parts.

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

   • NO, go to Step 2.

2. Disconnect Chassis Control Module (CCM) connector C002. Check fault code.

   Expected Result: The fault code clears.

   • YES, go to Step 3.

   • NO, go to Step 10.

3. Turn key start switch OFF. Disconnect rockshaft potentiometer, engine oil pressure sensor and air filter vacuum switch connectors C157, C103 and C109. Reconnect C002 at Chassis Control Module.

   Expected Result: The fault code clears.

   • YES, reconnect rockshaft potentiometer, engine oil pressure sensor and air filter vacuum switch one by one. Turn key start switch ON and check for presence of fault code F338 AFTER each device is reconnected. Install a new rockshaft potentiometer, engine oil pressure sensor or air filter vacuum switch as required. Check fault code and if no longer active the repair is complete.

   • NO, go to Step 4.

4. Disconnect CCM connector C002 and connector C157 from the Rear Main harness. Disconnect connectors C103 and C109 from the Front Main harness. Check for short circuit in the harnesses from C157-A to C157-B and from C103-A to C103-B. Also check for short to chassis ground from C002-24 or C109-2; from C002-5 or C103-B or C109-1 or C157-A; from C002-10 or C157-C; and from C002-31 or C103-C.

   Expected Result: There is a short in the circuit.

   • YES, go to Step 5.

   • NO, go to Step 7.

5. Disconnect CCM connector C002 and connector C157 from the Rear Main harness. Disconnect C008 from the Front Main harness. Check for short circuit in Rear Main harness from C157-A to C157-B, from C157-A to chassis ground, C157 to chassis ground and also from C002-24 to chassis ground.

   Expected Result: There is a short in the circuit.

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

   • NO, go to Step 6.

6. Disconnect connectors C008, C103 and C109. Check for short circuit in Front Main harness from C103-A to C103-B, from C103-B to chassis ground, from C109-1 to chassis ground and from C109-2 to chassis ground.

   Expected Result: There is a short in the circuit.

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

   • NO, go to Step 7.

7. Reconnect CCM connector C002. Turn key start switch ON. Measure voltage across C157-A and C157-B.

   Expected Result: The voltage measures approximately 5 DCV.

   • YES, go to Step 8.

   • NO, go to Step 10.

8. Turn key start switch OFF. Reconnect rockshaft potentiometer and recheck fault codes at the EMC.

   Expected Result: The fault code is not active.

   • YES, go to Step 9.

   • NO, go to Step 10.

9. Reconnect oil pressure sensor, air filter vacuum switch and Front Main harness connector C008.

   Expected Result: The fault code is not active.

   • YES, check for poor electrical contact at connectors and clean, or intermittent ground in harness. Check fault code and if no longer active the repair is complete.

   • NO, go to Step 10.

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

    Expected Result: The fault code is active.

    • YES, go to Step 11.

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

11. 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 12.

12. 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.