Giviner

Last summer I completed my swap of an LQ4 into my 2003 Jeep TJ. Initially, everything ran great, no issues whatsoever. I got all the parts from the same truck, a 2006 Silverado 2500HD. This motor has the DBW throttle control, and separate TAC computer. At first I had an intermittent problem where I would lose all throttle control and the motor would just idle. If I shut it off, jiggled the connector at the pedal, and restarted it, usually it would work again. However, the problem got progressively worse and now, no matter what I do, I have not throttle control.

I have 4 codes: P1125, P2120, P2125, P2138

Here is what I have done so far to diagnose:

- Checked continuity of TAC to pedal harness - good
- Checked for 5V reference signals from TAC to pedal - good
- Replaced pedal - no change, problem persists
- Checked continuity of TAC to throttle body harness - good
- Checked for proper reference voltage from TAC to throttle body - good
- Checked all connectors and pins for corrosion - no signs of corrosion
- Checked grounds for TAC - good

The next steps in my head would be to replace the TAC-pedal harness, then the TAC module itself........unless one of you smart folks can help me solve this problem. Any ideas before I go throwing more cash at this problem?

aaronsjeep

Hello Giviner,

I was wondering if you ever figured out your problem with the DBW on your Jeep? If you did, what did you find fixed the problem. I am having a very similar issue on my 2003 5.3 Jeep swap.

lsxyj

iTrader: (1)

did you use ur stock tj guages

OldCreek

iTrader: (1)

Giviner,

I'm having just about the exact same problems with the exact same codes (except P2138)...

Once, I replaced the pedal position sensor and it resolved the problem...for a few months and now it's back to its old ways.

I'm still working through this.

Wil