gremlins....limp mode
03-05-2011, 11:51 AM
#1
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gremlins....limp mode
ok...here is the story
had 8 or 9 passes at fontana yesterday with no issues. decided to do one more pass to try for an 11.7x.
after the burnout...while i was brake stalling (2200-2300) i got reduced engine power and a solid engine light...not flashing. the truck locked out into limp mode.
got off the track and restarted it...it was fine. just the SES light.
plugged in an EFI live scanner and only code it retrieved was a low fuel level sender 1 (forgot the actual code) my fuel sender has not worked for about a year (long story). I filled up and it took 19 gallons...still had at least 6 in it.
fuel pressure good, afr good.
shut it down and restarted again and the light had cleared.
started my drive back and 2.5 miles into it...limp mode again.
tried to get it running again on the side of the road but about every 3rd ignition cycle it would start in reduced engine power mode....idle at 2000 rpm and no throttle control.
chase to to the rescue with a trailer.....drove it on and off the trailer with no issues.
Waiting to get my hands on a tech 2 and a spare x link...think the x link may be shitting on my parade.
ANY THOUGHTS???
had 8 or 9 passes at fontana yesterday with no issues. decided to do one more pass to try for an 11.7x.
after the burnout...while i was brake stalling (2200-2300) i got reduced engine power and a solid engine light...not flashing. the truck locked out into limp mode.
got off the track and restarted it...it was fine. just the SES light.
plugged in an EFI live scanner and only code it retrieved was a low fuel level sender 1 (forgot the actual code) my fuel sender has not worked for about a year (long story). I filled up and it took 19 gallons...still had at least 6 in it.
fuel pressure good, afr good.
shut it down and restarted again and the light had cleared.
started my drive back and 2.5 miles into it...limp mode again.
tried to get it running again on the side of the road but about every 3rd ignition cycle it would start in reduced engine power mode....idle at 2000 rpm and no throttle control.
chase to to the rescue with a trailer.....drove it on and off the trailer with no issues.
Waiting to get my hands on a tech 2 and a spare x link...think the x link may be shitting on my parade.
ANY THOUGHTS???
03-06-2011, 12:15 PM
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CODES:
P0120: Throttle Position Sensor 1 circuit malfunction
P0220: Throttle Position Sensor 2 circuit malfunction
P1516: Throttle Actuator Control (TAC) Module Throttle Actuator Position Performance
P1518: Throttle Actuator Control (TAC) Module Serial Data Circuit
Doing some reading..even from the TorqueRush site. Going to checek all connections and ground. Have a feeling it is the xLink though. Reynaldo had similar problems. I have mine mounted to the side of the blower case...not sure if it a heat/vibration issue.
P0120, P0220 and P1516 can be caused by broken wiring in the DBW system.
P1518 is related to low battery voltage or bad grounds. Battery is strong and I have checked my grounds.
P0120: Throttle Position Sensor 1 circuit malfunction
P0220: Throttle Position Sensor 2 circuit malfunction
P1516: Throttle Actuator Control (TAC) Module Throttle Actuator Position Performance
P1518: Throttle Actuator Control (TAC) Module Serial Data Circuit
Doing some reading..even from the TorqueRush site. Going to checek all connections and ground. Have a feeling it is the xLink though. Reynaldo had similar problems. I have mine mounted to the side of the blower case...not sure if it a heat/vibration issue.
P0120, P0220 and P1516 can be caused by broken wiring in the DBW system.
P1518 is related to low battery voltage or bad grounds. Battery is strong and I have checked my grounds.
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03-06-2011, 12:40 PM
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sounds like the xlink like i said.
one other somewhat common problem with the gmt-800 is the wires to factory tb. withing the first 6-7 inches of the connector to the original tb the wires can get broken inside and appear fine but the copper is actually broken. best way is to hold easy wire individually , near the connector and about 7 inches back , remove the factory tape and split loom and pull gently holding the wire in each hand to see if it breaks the insulation since the copper is broken it should be pretty easy to break . i had to do a few of these @ gm and on my truck at one point . you then need a new pigtail for the tb and splice it in. gm thought it would be a good idea to sell the new connector with all white wires instead of the color coded on the factory end.
one other somewhat common problem with the gmt-800 is the wires to factory tb. withing the first 6-7 inches of the connector to the original tb the wires can get broken inside and appear fine but the copper is actually broken. best way is to hold easy wire individually , near the connector and about 7 inches back , remove the factory tape and split loom and pull gently holding the wire in each hand to see if it breaks the insulation since the copper is broken it should be pretty easy to break . i had to do a few of these @ gm and on my truck at one point . you then need a new pigtail for the tb and splice it in. gm thought it would be a good idea to sell the new connector with all white wires instead of the color coded on the factory end.
03-06-2011, 01:15 PM
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Thanks Chase.
I read the same stuff...gonna check the wires now and also check the stuff on the x link that torquerush mentions in their troubleshooting doc. I hope its something easy...then on to getting the rims to stick to the tires. lol
I read the same stuff...gonna check the wires now and also check the stuff on the x link that torquerush mentions in their troubleshooting doc. I hope its something easy...then on to getting the rims to stick to the tires. lol
03-06-2011, 03:19 PM
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Most common problems that I have seen on the stock trucks with those codes are the wiring like mentioned above (half of the time it is so intermittant it is an educated guess) and the throttle body itself but it mostly the wiring near the throttle body.