A little DTC help for a LS1 noob
03-15-2011, 11:10 PM
#1
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A little DTC help for a LS1 noob First of all, lovin' this site...Although, all the information can be a little overwhelming at times 
Anyways, I'm in the midst of a 87' Buick T-Type LS swap. Have a 5.3 sitting in the car now with a modified 2000 truck harness and computer minus a few accessories along with the MAF. Fired the car for the first time the other night and it hit instantly. Ran it for about 15 mins at idle and couldn't of asked for anything more from it....My buddy that's been helping me some on the project, reached down and blipped the throttle and the car died. Have been unable to get the car to idle since. Turn the key, the car hits and immediately dies...Almost like a VATS issue, but I have that disabled in the HPTuner software. Here's 4 of the 5 codes that the scanner shows:
[PCM] P0122 - Throttle Position (TP) Sensor Circuit Low Voltage (Pending) (Immature)
[PCM] P0452 - Fuel Tank Pressure Sensor Circuit Low Voltage (Pending) (Old) (Current) (Immature)
PCM] P1122 - Throttle Position (TP) Sensor Circuit Intermittent Low Voltage (Pending) (History) (Immature)
[PCM] P1635 - 5 Volt Reference Circuit (Pending) (Current) (Immature)
[PCM] P1639 - 5 Volt Reference 2 Circuit (Pending) (Current) (Immature)
From what research I've done, I believe the Fuel Tank Pressure Sensor and TPS are both tied to the same 5V circuit. My question is, since I am not running a Fuel Tank Pressure Sensor, could this be causing the TPS and 5V reference issues I'm seeing??? If so, how do I go about correcting it? Any help appreciated as I'm new to the LS world. Trying to work out the bugs on this engine before I drop the built 6.0 in it. Thx Scott
Anyways, I'm in the midst of a 87' Buick T-Type LS swap. Have a 5.3 sitting in the car now with a modified 2000 truck harness and computer minus a few accessories along with the MAF. Fired the car for the first time the other night and it hit instantly. Ran it for about 15 mins at idle and couldn't of asked for anything more from it....My buddy that's been helping me some on the project, reached down and blipped the throttle and the car died. Have been unable to get the car to idle since. Turn the key, the car hits and immediately dies...Almost like a VATS issue, but I have that disabled in the HPTuner software. Here's 4 of the 5 codes that the scanner shows:[PCM] P0122 - Throttle Position (TP) Sensor Circuit Low Voltage (Pending) (Immature)
[PCM] P0452 - Fuel Tank Pressure Sensor Circuit Low Voltage (Pending) (Old) (Current) (Immature)
PCM] P1122 - Throttle Position (TP) Sensor Circuit Intermittent Low Voltage (Pending) (History) (Immature)
[PCM] P1635 - 5 Volt Reference Circuit (Pending) (Current) (Immature)
[PCM] P1639 - 5 Volt Reference 2 Circuit (Pending) (Current) (Immature)
From what research I've done, I believe the Fuel Tank Pressure Sensor and TPS are both tied to the same 5V circuit. My question is, since I am not running a Fuel Tank Pressure Sensor, could this be causing the TPS and 5V reference issues I'm seeing??? If so, how do I go about correcting it? Any help appreciated as I'm new to the LS world. Trying to work out the bugs on this engine before I drop the built 6.0 in it. Thx Scott
06-01-2012, 04:02 PM
#3
Sorry to bump this thread after a years. This is only for people looking to figure out this issue. Try checking your wiring harness behind the ECM. A smaller group of wires in black conduit will be coming out of the firewall on the passenger side. Remove the ECU to gain access. There's a self tapping screw that this harness may have rubbed through. Open the conduit and repair wires if necessary and secure harness away from screw!
