P0733

P0733 sets when the TCM commands 3rd gear and the calculated input/output ratio falls outside the expected 3rd-gear window (typical 1.00:1 on a 4-speed direct-drive 3rd, around 1.14-1.20 on a 5-speed, varies on 6-8 speeds) by more than 5-7% for 2-5 seconds under load. Same diagnostic logic as P0732 but specific to the 3rd-gear apply elements (typically a clutch pack rather than a band on most modern transmissions). Cheap diagnostics first: ATF level at the spec temperature, then a pressure-tap test for line pressure across the throttle range, then scan-tool solenoid command vs reported gear-state during a road test. Watch the calculated ratio in live data during a 2-3 upshift, the ratio should snap from 1.62 to 1.00 within 0.5-1 second on a healthy 4-speed, a slow ramp or hung-up intermediate ratio is the signature of clutch slip. Ohm the shift solenoids and compare against spec. Expensive misdiagnosis: the 3rd-gear apply element on most platforms is buried deep in the trans and requires a full teardown to service, do not authorize the teardown until you have verified line pressure is in spec under load and ruled out a stuck or leaking shift solenoid, a $200 valve-body rebuild often eliminates the symptom because the actual fault was solenoid bore wear leaking apply pressure rather than worn clutches.

Vehicle-specific patterns: 2000-2007 GM 4L60E sees P0733 from 3-4 clutch pack wear, the 3-4 clutches are the chronic wear point on this trans and the failure typically arrives between 120-180K miles, a rebuild with updated 3-4 clutch hardware is the standard fix; 2003-2010 Volvo S60/XC90/Saab 9-3 with Aisin AW55-50SN/55-51SN throws P0733 from valve-body bore wear, the solenoids leak pressure past worn bores and the fix is a sonnax valve-body rework kit; 2005-2010 Ford Five Hundred/Freestyle with CVT (ZF CFT30) has been retired by Ford with extended warranties, the CFT30 fails the steel-chain interface and is not economically rebuildable. Estimated repair: $300 to $4,200.