Troubleshooting Procedure For Fault Code 501-10 (DMC Fault) Caterpillar

Problem:

Reports indicate several of the above engines have generated Fault Code 501-10 (Noisy Ignition Signal Cylinder 1). The following is one troubleshooting technique that seems to help solve this problem. This troubleshooting technique may also resolve the 501-12 (No Ignition Signal Cylinder 1), and the 190-12 (No Flywheel Signal) Fault Codes.

Solution:

Other symptoms that were noted besides the Fault Code 501-10 included continuous E06, E07, and E08 Fault Codes on the Customer Communication Module (CCM). Note that the engine monitoring operation was through the CCM on a lap top computer. A CCM connected to a site Programmable Logic Controller should also display the same fault codes, if the problem is due to a communication problem on communication link two. The observation of the CCM fault codes lead to a troubleshooting sequence that is similar to an 819-12 Fault Code.

1. Start by inspecting all wiring on communication link two. A poor connection or incorrect wiring could cause this problem.

2. Shut down the engine and disconnect each component on communication link two until the CCM no longer displays the E06, E07, and E08 Fault Codes. Instead, the CCM should only display an occasional (once per minute) E05 and E06 Fault Code.

The items of communication link two include the:

* Computerized Monitoring System (CMS)

* Customer Communication Module (CCM)

* Digital Diagnostic Tool (DDT)

* Detonation Mixing Control (DMC)

* Engine Control Module (ECM)

* 240 ohm termination resistor in the engine mounted junction box that is installed between the negative side of communication link two and battery negative.

IT may be possible that the CCM is the root cause of the fault, so it may be necessary to operate the engine for a period of time without this devise to determine if it is the cause for a communication failure on communication link two.

We removed the 240 ohm termination resistor. This caused the fault codes to decrease from once every 30 minutes to once every 12 hours. We reinstalled 240 ohm termination resistor after we found a faulty CMS panel, and the unit continued to run.

A decision has not been made about the 240 ohm termination resistor on communication link two in the junction box. However, this resistor may be playing a role in the problem. The 240 ohm termination resistor could be left out if the problem continued.

Your feedback would be appreciated to help determine if this is the only root cause for this problem. Please contact the Gas Engine Customer Service Representative at:

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