Having a little bit of an issue here regarding the TPS. Maybe somebody has some advice in regards to this.

Vehicle is turbocharged and is running Haltech EMS. Hal from Dynosty gave me a basemap to use which is fine. However the issue comes up with the TPS. The car is very slow revving. I did the calibration with the Haltech and the voltage numbers are normal. The haltech also shows the TPS voltage to be normal with the pedal released and depressed.

The Mil light came on and the only code in the system is P0227 which is
Accelerator pedal position sensor 1 circuit low input. According to the fsm the code is detected when An excessively low voltage from the APP sensor 1
is sent to ECM and the possible cause is the Harness or connectors (The APP sensor 1 circuit is open or shorted.)

Anyway upon further reading of the fsm, it states that

"The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10 degrees.
The ECM regulates an opening speed of approx. 5 seconds to an opening of 10 degrees. So, the acceleration will be poor"

That is basically what I am experiencing. The car does not want to rev at under load or no load. I did the relearn procedures that the fsm suggests and i am still not having any luck.

Any suggestions guys? Could a bad ground somewhere be causing this issue since the voltage is normal?

 

A bad ground means there is resistance at the connection. How much that affects the voltage depends on how much current is flowing through the circuit. More current=more voltage drop. Electronics normally operate at low currents.

The bad thing is that bad grounds often have variable resistance, so the voltage drop will be variable, too.

If you're seeing the correct voltage under operating conditions, the normal current is flowing through the circuit. That would suggest there's no problem with the grounding.

 

Thanks for that info. I will keep it in mind.

Yesterday i decided to check for the ground circuit and found something interesting. There is no continuity between pin 3 on the APP connector and pin 58 on the ecu connector.

And I think according to the fsm that it should exist.

CHECK APP SENSOR 1 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch “OFF”.
2. Check harness continuity between APP sensor terminal 3 and engine ground.
Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.

And According to the fsm, the ground wire goes directly from the app connector pin 3 directly to the ecu connector pin 58. There is a sub connector in the middle though. I am going to look further more into it and see what exactly went wrong here.

 

Update to the issue. Found the problem which was a bad ground.

 

which ground was bad????

 

It was one of the ground wires that are bolted to the front timing cover on the top.

 

Yea that's pretty common... the engine only has one ground point on the chassis... it Y's from the passenger side chassis rail to the front/back timing cover. If any of those 3 connections are loose or corroded it will spell trouble. Hopefully the engine doesn't end up grounding through the ECU instead.