Throttle Position Sensor
Thread Starter
Advanced
Joined: Sep 2005
Posts: 86
Likes: 1
From: Tampa Florida
Throttle Position Sensor
So I had been getting codes for a while and finally replaced my throttle position sensor. Thought it would fix the problem but apparently not. I am still getting these codes:
P1120 TP Sensor 1 Circuit
P1220 TP Sensor 2 circuit
P1221 TP Sensors 1, 2 Performance
P1516 Command vs actual throttle position performance (TAC module)
I also cleaned up the grounds with a dremel and electrical cleaner and checked the wiring and battery. All seems fine. The codes trigger the dreaded Reduced Power mode. I can reset them and they go away but come back at random.
Anyone know anything about this? Would be great if someone can help a brother out.
P1120 TP Sensor 1 Circuit
P1220 TP Sensor 2 circuit
P1221 TP Sensors 1, 2 Performance
P1516 Command vs actual throttle position performance (TAC module)
I also cleaned up the grounds with a dremel and electrical cleaner and checked the wiring and battery. All seems fine. The codes trigger the dreaded Reduced Power mode. I can reset them and they go away but come back at random.
Anyone know anything about this? Would be great if someone can help a brother out.
Race Director
Joined: Jul 2004
Posts: 16,795
Likes: 62
From: Lake Havasu City, AZ
I see from your profile that you have a VaraRam installed.
Did you also install their plastic velocity stack?
It can shift and interfere with the movement of the throttle body blade.If you have it installed check its fit or remove it.... and see what happens.
Did you also install their plastic velocity stack?
It can shift and interfere with the movement of the throttle body blade.If you have it installed check its fit or remove it.... and see what happens.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
The throttle circuit is a DISCRETE CIRCUIT. It connects the TPS, PCM, TAC and Accelerator position switch together and there are no "chassis" ground for that circuit.
You should examine the TAC module wiring for acid damage or rodent damage. Also check the connector and female pins in each connector and make sure that there clean and tight.
The TAC module is in the passengers fender well on the outside of the PCM:
BC
BC
You should examine the TAC module wiring for acid damage or rodent damage. Also check the connector and female pins in each connector and make sure that there clean and tight.
The TAC module is in the passengers fender well on the outside of the PCM:
BC
BC
Thread Starter
Advanced
Joined: Sep 2005
Posts: 86
Likes: 1
From: Tampa Florida
You never cease to amaze me with your level of knowledge on these cars Bill. Thanks for the info. A couple questions though; do I need to remove the passenger side fender to get to the TAC module? Also, does anyone have a part number? Thanks in advance.
1st Gear
Joined: May 2009
Posts: 1
Likes: 0
Having TPS Issues
Having same issues. So far I have replaced the TPS on the Throttle body and the TAC module with no luck. Checked all pins and connections for corrosion. None. Cleaned grounds 100% as you suggest. Even took it to Chevy "stealership" and was told that the issue was related to the HID headlights I have installed. Somebody HELP!!!!!
Codes 1221, 1120, etc. In addition, I get the resultant 1278 code....
At my wit's end....
Codes 1221, 1120, etc. In addition, I get the resultant 1278 code....
At my wit's end....
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