1999 Dodge Durango P0202 and P0207 Codes: Troubleshooting Injector Circuit Faults
On Saturday, while driving my 1999 Dodge Durango on the interstate at approximately 65 MPH, I noticed the vehicle began surging significantly. The engine would suddenly surge by several hundred RPMs, and the check engine light activated. On Monday, during a commute to work, the check engine light turned off unexpectedly. On Tuesday, I connected a diagnostic tool and retrieved two fault codes: P0202 (Injector Circuit Malfunction for Cylinder 2) and P0207 (Injector Circuit Malfunction for Cylinder 7). I reviewed previous discussions and found that Jeff Compton suggested checking the Throttle Position Sensor (TPS), noting it's responsible in about 90% of cases, with wiring issues accounting for the remaining 10%. However, I'm confused—why isn't there a P0123 TPS fault code if the TPS is faulty? My vehicle is a 4x4 equipped with a 5.2L V8 engine. The surging behavior suggests potential fuel delivery issues, but I want to ensure I'm diagnosing correctly before replacing parts. I understand that if an injector circuit were truly malfunctioning (e.g., due to no injection or shorted injection), the vehicle would typically run rough or misfire. Since my truck runs smoothly under normal conditions, this makes me question whether a TPS issue is likely. A reliable scan tool should show TPS readings above 5% at idle with the throttle fully released—this would indicate a faulty sensor. Many online guides suggest replacing injectors or wiring harnesses due to perceived electrical noise from the TPS, but I believe this may be an overreach without proper diagnostics. For best results, I recommend using only OEM or dealer-grade parts when performing repairs.
It's uncommon for a Throttle Position Sensor (TPS) on a Dodge to generate P0202 or P0207 codes directly. While some sources claim TPS-related electrical noise can cause injector circuit faults, this is typically due to misinterpretation of sensor signals rather than actual TPS failure. A key point: if the engine were truly experiencing an injector malfunction (such as no fuel injection or shorted injection), it would exhibit symptoms like rough idling, stalling, or surging under load—symptoms not consistently present in this case. Since the vehicle runs smoothly otherwise, a faulty TPS is less likely. A proper scan tool should show TPS readings exceeding 5% at idle with the throttle fully released—a value that indicates an abnormal sensor output. Many DIYers replace injectors or wiring harnesses without verifying TPS data, which can lead to unnecessary expenses. Always verify TPS readings before replacing components. When in doubt, use only OEM or dealer-grade parts for reliable results.