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P0341 and P0652 Fault Codes on 2003 Ram 3500 5.9L - After Unleaded Fuel Contamination

Model: 03 ram 5.9l Fault Code: P0341 Posted: 2012-10-25 14:34

Vehicle: 2003 Dodge Ram 3500 5.9L V8 Fault Codes: P0341, P0652 Symptoms: Occasional coughing, stalling, and rough idle; some driving conditions result in smooth operation. Initial diagnosis revealed P0341 (Camshaft Position Sensor A Circuit Malfunction) and P0652 (Fuel Pump Control Circuit Malfunction). The owner replaced the camshaft position sensor (CMP), but symptoms persisted. Further investigation uncovered that unleaded fuel had been accidentally added to the tank. The fuel system was drained, the fuel tank cleaned, and new components were installed: a new injector pump, a new AirDog fuel pump, and a new fuel pressure sensor. After these repairs, the truck runs smoothly most of the time with occasional hiccups. A recent visit to a car wash where engine degreasing was performed resulted in immediate improvement—trucking ran perfectly upon return. Note: The P0652 code is particularly concerning given the recent replacement of the CMP sensor. This suggests potential issues with wiring, connector corrosion, or harness pinching during installation. It is recommended to verify voltage readings on the dark green/orange and light blue/white wires (which serve as 5V reference signals) at the CMP sensor.

Related fault codes

P0341P0652

Comments (4)

Anonymous 2012-10-25 15:19

I'm confused—this situation often occurs with Cummins engines. Someone accidentally added unleaded fuel to the tank, which led to a long purge cycle and subsequent issues. After replacing filters and possibly the separator, you now experience rough idle and only P0341 and P0652 codes. Given that the CMP sensor was recently replaced, I suspect problems with the connector—check for corrosion or pinched wiring in the harness. Did you source the sensor from Dodge? If so, verify the voltage on the dark green/orange (DkGrn/Org) and light blue/white (LtBlu/Wht) wires at the CMP sensor. These are 5V reference signals that should remain stable.

Anonymous 2012-10-25 19:43

I posted this wire information without asking—do you have access to a reliable OBD2 scanner capable of reading live data? This would help confirm real-time sensor readings and rule out intermittent faults.

Anonymous 2012-10-26 09:13

Yes, I've installed new fuel filters and completed the purge cycle. My current scanner does not support live data monitoring. A few other fault codes appeared initially but did not return after the repair. Since the incident, I’ve driven the truck for two months with only occasional hiccups. After a recent car wash where I degreased the engine, it ran exceptionally well upon returning to the shop—this suggests possible contamination or residue buildup.

Anonymous 2012-10-26 09:41

Trying to gather more details to assist—what were the other fault codes you initially saw? Can your scanner read manufacturer-specific Pxxxx codes (like P0652)? Is there a freeze frame data available for these events? Also, check if any aftermarket modifications, such as chips or remote start systems, could be contributing to the issue.