C5 cranks but will not start
Thread Starter
Heel & Toe
Joined: Jun 2007
Posts: 20
Likes: 1
C5 cranks but will not start
C5 cranks but will not start. Checked error codes. P1516 throttle actuator control tac
P2108 throttle actuator control module
U0107 lost comm with throttle actuator control.
I am going to replace the module first.
Anybody have a recommendation how to proceed with this diagnostics and repair before i begin replacing things.
P2108 throttle actuator control module
U0107 lost comm with throttle actuator control.
I am going to replace the module first.
Anybody have a recommendation how to proceed with this diagnostics and repair before i begin replacing things.
Racer
Joined: Jun 2004
Posts: 270
Likes: 67
From: Montana
You can see if throttle body blade is operating. With ignition key on position and plenum off. Press down on gas pedal to see movement. Verify blade position relative to the pedal. If that doesn’t work. You will need to verify power is going to TAC module. Check the ground wire on the engine block just above the starter. This same ground point for the negative side of battery. You will see a large and small gauge wire there...the smaller one is the TAC ground.
I ran into this problem during my engine install... my ground wire was bad.
i would look for wiring schematic for TAC online and verify wiring is good by using multimeter...
I ran into this problem during my engine install... my ground wire was bad.
i would look for wiring schematic for TAC online and verify wiring is good by using multimeter...
Last edited by robmiz; Sep 22, 2019 at 06:20 PM.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,628
Likes: 4,074
From: Cape Coral, Florida
Sometimes low battery voltage will cause a P1516 to set...I’d load test the battery...also P2108 doesn’t look familiar and also U0107...the TAC module is not one of the modules on the serial data network so it wouldn’t be a “can’t comm. with TAC control “ !!...well I wouldn’t replace the TAC module first...if the PCM thinks the car is in “clear flood crank” mode ( gas pedal to the floor while cranking) the car will be a cranking no start !!...I believe throttle position has to be greater than 80%...a quick test is remove an fuel injector connector and with 12 volt test light connected to battery positive probe the striped wire while cranking...if the test light doesn’t blink as the engine is cranked you don’t have injector control...this is what happens during a “clear flood crank”...NO injector control...might give you some direction !!
Thread Starter
Heel & Toe
Joined: Jun 2007
Posts: 20
Likes: 1
Turned key off and on at least 10 times still wont start.
Will check grounds. throttle position, test light and connector to throttle actuator control module for corrosion.
This is a good start. Thanks for advice. Will post what results i achieve.
Will check grounds. throttle position, test light and connector to throttle actuator control module for corrosion.
This is a good start. Thanks for advice. Will post what results i achieve.
