2007 Silverado 2500HD U1010 P1810 C035: Troubleshooting Speed Sensor, TPM Connection & Transmission Codes
I recently performed a complete fluid service on my 2007 Silverado 2500HD 4x4 (6.0L V8), including transmission fluid and filter, transfer case oil, both differential oils, and engine oil with filter. After the service, the check engine light came on. I took the truck to O'Reilly's for an OBD2 scan and received three diagnostic codes: U1010 (Loss of Communication with Transmission Power Module), P1810 (Transmission Forward Position Switch Fault), and C035 (Left Front Wheel Speed Sensor Circuit). My questions are as follows: - C035 relates to the left front wheel speed sensor. I've noticed a grinding noise or vibration when turning sharply to the right under high acceleration in 2WD. I’ve heard that worn bearings can cause this symptom—does that sound plausible? Are these symptoms related to the code? - U1010 and P1810 both relate to transmission components. Are they connected? Could one fault have triggered the other? How can I verify if either is actually present or intermittent? - After the OBD2 scan, the check engine light turned off. The technician said he did not reset it due to insurance policy requirements. Will the light automatically turn off after reading codes, or does a reset still need to be performed? Vehicle details: 2007 Silverado 2500HD 4x4, 6.0L engine, 113,000 miles.
Reading OBD2 codes does NOT clear them — the fault codes remain stored in the ECU. Check if your ABS warning light comes on at startup for about 5 seconds. If it's always doing so, that may indicate a problem with the wheel speed sensors or ABS system — let me know. How is transmission shifting? If it feels normal post-service, operate the truck under various conditions and monitor whether the codes return. C035 indicates a left front wheel speed sensor circuit fault. A scanner can show actual sensor signal data — this helps determine if the issue is hardware failure or intermittent. Note: Wheel speed sensors are often prone to failure; this code may be an ABS-related hard fault, which explains why you're being asked about the bulb check. Grinding noise during sharp turns? Check CV joints using a proper procedure (available online). A small amount of play is normal, but excessive movement could point to wear. For U1010, two common causes come to mind: remote starter system or ignition switch issues. Verify if these codes reappear after driving — also check whether your truck has a remote start feature. If not, the ignition key may be the culprit.