2007 toyota sienna, remote start

I have a customer that had a remote start installed on a 2007 Toyota Sienna a month back and has just called to say that he is having trouble getting the car to start with the key. He says that it will crank a while and sometimes he has to try a few times before it will start. The bypass used was a 556U with a second key. Has anyone encountered this problem? Is it possible for the transponder ring to be interfereing with the key in the ignition? I know that the 556u isn't energized when not remote started, but I don't see any other way the car wouldn't start instantly. Could the ring itself be interfereing? Any help would be appreciated.

I need the info sheet for the 2007 Toyota Sienna if anyone has it.

Definitely follow enice's advice to start the troubleshooting. If the U is disconnected and it still gives problems you know the issue lies elsewhere. Here is what Audiovox lists for the 07 Sienna:                 #512077: 2007 TOYOTA SIENNA MINIVAN      Audio/Mobile Video                                              WIRE          COLOR          POLARITY          LOCATION           Battery          BLUE / YELLOW          (+)          RADIO HARNESS           Accesory          GRAY          (+)          RADIO HARNESS           Ground          WHITE/ BLACK          (-)          RADIO HARNESS           Illumination          GREEN          (+)          RADIO HARNESS           Power Antenna          PINK/BLUE          (+)          RADIO HARNESS           LF Speaker (+)          PINK           LF Speaker (-)          VIOLET           RF Speaker (+)          GREEN           RF Speaker (-)          BLUE           LR Speaker (+)          BLACK           LR Speaker (-)          YELLOW           RR Speaker (+)          RED           RR Speaker (-)          WHITE           Radio Security          YES           Security                                              WIRE          COLOR          POLARITY          LOCATION           Battery          WHITE/ RED          (+)          IGNITION SWITCH HARNESS           Ignition 1          BLACK          (+)          IGNITION SWITCH HARNESS           Starter 1          BLACK / YELLOW          (+)          IGNITION SWITCH HARNESS           All Door Trigger          BLUE          (-)          IGNITION SWITCH HARNESS           Domelight Super          BLUE          (-)          IGNITION SWITCH HARNESS           LF Latch          RED / YELLOW          (-)          AT BCM MODULE BEHIND DRIVERS SIDE OF DASH NEAR STEERING COLUMN                     PIN #14           RF Latch          RED / YELLOW          (-)          AT BCM MODULE BEHIND DRIVERS SIDE OF DASH NEAR STEERING COLUMN                     PIN #23           LR Latch          GRAY          (-)          AT BCM MODULE BEHIND DRIVERS SIDE OF DASH NEAR STEERING COLUMN                     PIN #15           RR Latch          RED / WHITE          (-)          AT BCM MODULE BEHIND DRIVERS SIDE OF DASH NEAR STEERING COLUMN                     PIN #16           Trunk Trigger          GREEN / WHITE          (-)          AT BCM MODULE BEHIND DRIVERS SIDE OF DASH NEAR STEERING COLUMN                     PIN #25           Hood Trigger          RED / WHITE          (-)          AT BCM MODULE BEHIND DRIVERS SIDE OF DASH NEAR STEERING COLUMN                     PIN #10           Alarm Disarm          BLUE/BLACK          (-)          AT BCM MODULE BEHIND DRIVERS SIDE OF DASH NEAR STEERING COLUMN                     PIN #21           Parking Lights          GREEN/ BLACK          (-)          IGNITION SWITCH HARNESS           Convenience                                              WIRE          COLOR          POLARITY          LOCATION           Headlights-Lo          RED / GREEN          (-)          AT VEHICLE LIGHT SWITCH HARNESS           LF Pk Lt Bulb          GREEN          (+)          AT FRONT LEFT PARKING LIGHT           RF Pk Lt Bulb          GREEN          (+)          AT FRONT RIGHT PARKING LIGHT           LR Pk Lt Bulb          GREEN          (+)          AT REAR LEFT PARKING LIGHT           RR Pk Lt Bulb          GREEN          (+)          AT REAR RIGHT PARKING LIGHT           All Hazrd Lights          BLACK/ ORANGE          (-)          AT VEHICLE HAZARD SWITCH HARNESS           Wipers-Lo          BLUE/BLACK          (+)          AT VEHICLE WIPER SWITCH HARNESS           Wipers-Hi          BLUE/ORANGE          (+)          AT VEHICLE WIPER SWITCH HARNESS           Remote Start                                              WIRE          COLOR          POLARITY          LOCATION           Battery          WHITE/ RED          (+)          IGNITION SWITCH HARNESS           Ignition 1          BLACK          (+)          IGNITION SWITCH HARNESS           Ignition 2          BLACK / YELLOW          (+)          IGNITION SWITCH HARNESS           Accessory 1          PINK          (+)          IGNITION SWITCH HARNESS           Starter 1          BLACK / YELLOW          (+)          IGNITION SWITCH HARNESS           Anti-Theft Type          UNIVERSAL IMMOBILIZER           Anti-Theft Descript          THE KEY SENDS AN RF SIGNAL TO THE BCM MODULE THROUGH AN ANTENNA LOCATED AROUND THE IGNITION CYLINDER           Key Sense          BLUE/BLACK          (-)          IGNITION SWITCH HARNESS           Tachometer          GREEN/ RED          (AC)          AT ECM MODULE TO RIGHT OF GLOVEBOX                     PIN #5           Speed Sense          VIOLET/WHITE          (AC)          AT ECM MODULE TO RIGHT OF GLOVEBOX                     PIN #17           Parking Lights          GREEN/ BLACK          (-)          IGNITION SWITCH HARNESS           Brake Lights          GREEN / WHITE          (+)          AT SWITCH ABOVE BRAKE PEDAL           Reverse Lights          RED / BLACK          (+)          IN HARNESS AT LIGHT           Horn          GREEN/ BLACK          (+)          IGNITION SWITCH HARNESS           Modules                                              WIRE          LOCATION                               Module 1          ECM - BEHIND RIGHT SIDE OF DASH TO RIGHT OF GLOVEBOX           Doorlocks/Windows                                              WIRE          COLOR          POLARITY          LOCATION           Power Unlock          GREEN          (-)          AT BCM MODULE BEHIND DRIVERS SIDE OF DASH NEAR STEERING COLUMN                     PIN #12           PowerLock          RED / YELLOW          (-)          AT BCM MODULE BEHIND DRIVERS SIDE OF DASH NEAR STEERING COLUMN                     PIN #9           Driver Mtr Unlock          BLUE/RED          (+)          IN HARNESS IN DRIVERS KICKPANEL           Driver Mtr Lock          YELLOW/BLACK          (+)          IN HARNESS IN DRIVERS KICKPANEL           LF Window Up          RED          (REV)          AT VEHICLE MASTER WINDOW SWITCH IN DRIVERS DOOR           LF Window Dn          GREEN          (REV)          AT VEHICLE MASTER WINDOW SWITCH IN DRIVERS DOOR           RF Window Up          RED / BLUE          (REV)          AT VEHICLE MASTER WINDOW SWITCH IN DRIVERS DOOR           RF Window Dn          BLACK/ WHITE          (REV)          AT VEHICLE MASTER WINDOW SWITCH IN DRIVERS DOOR           LR Window Up          PINK          (REV)          AT VEHICLE MASTER WINDOW SWITCH IN DRIVERS DOOR           LR Window Dn          BLUE/RED          (REV)          AT VEHICLE MASTER WINDOW SWITCH IN DRIVERS DOOR           RR Window Up          RED / BLACK          (REV)          AT VEHICLE MASTER WINDOW SWITCH IN DRIVERS DOOR           RR Window Dn          BLACK          (REV)          AT VEHICLE MASTER WINDOW SWITCH IN DRIVERS DOOR           Sunroof Open          RED / WHITE          (-)          AT SUNROOF SWITCH IN OVERHEAD CONSOLE           Sunroof Close          RED / BLUE          (-)          AT SUNROOF SWITCH IN OVERHEAD CONSOLE                       Note: Audiovox makes no representation or warranty with respect to the above information including its accuracy, completeness, or its freedom from third parties' proprietary rights. Audiovox disclaims all liability or responsibility for errors or omissions therein or any decision made by the recipient in reliance thereon. The installer must verify any circuitry with the proper test equipment prior to installation.                   Installer, IT support, and FFL. I need less hobbies.