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2002 Grand Caravan Sport 3.3L: P0700, P0456, and P0605 Diagnostic Help - Transmission Not Shifting Out of 2nd Gear

Model: 02 Grand Caravan Fault Code: P0456 Posted: 2016-08-25 09:04

I own a 2002 Grand Caravan Sport with a 3.3L engine. The tachometer readings are higher than normal, and the vehicle appears to be stuck in second gear—unable to shift into higher gears. I'm seeking advice before taking it to a transmission shop. The check engine light is on, and I've pulled up fault codes: P0700 (Transmission Control Module Fault), P0456 (Evaporative Emission System Leak - small leak), and P0605 (Powertrain Control Module ROM Error). Any insights into these codes and how they might relate to the shifting issue would be greatly appreciated.

Related fault codes

P0456P0600P0700

Comments (2)

Anonymous 2016-08-25 09:47

P0456 indicates a small leak in the evaporative emission system—this is typically not directly related to transmission shifting but may require servicing if it persists. P0605 points to a ROM error in the Powertrain Control Module (TCM), which could affect transmission operation and shift timing. P0700 signifies a fault in the transmission control unit's readout memory, suggesting potential issues with gear shifting logic or sensor input. These codes may be interrelated due to TCM malfunction.

Anonymous 2016-08-25 12:30

Sorry for the lack of direct help. P0700 suggests a transmission-related fault, possibly related to shift timing or gear selection. P0605 indicates a failure in the Powertrain Control Module (TCM) ROM—this is critical as it stores essential programming data. A faulty TCM can cause erratic shifting behavior and may be the root of the second-gear issue. Recommended action: Replace the Transmission Control Module, perform a quick learn procedure to reprogram pinion factor settings, and conduct a 41TE Transmission Verification Test (Version 1) to confirm proper operation post-replacement.