NGC3 TPS Help

[CaptainBanana]

Can someone help me make sense of this?

I’m troubleshooting a P2074 on my 2005 TJ with an NGC3 PCM. I’ve been logging the TPS through both an OBD scanner and HP Tuners, and here’s what I’m seeing:

At closed throttle, I’m getting ~0.6V, which is fine.

At wide open throttle (WOT), I’m only seeing about 2.6V.

This 2.7V reading is consistent across all methods: OBD scanner, HP Tuners, and directly with a multimeter — regardless of whether I ground to the connector, battery, or engine.

The 5V reference is solid, so that’s not the issue.

Now here’s the odd part:
With the TPS removed and manually rotated, it can output up to 4.7V — but only when turned beyond the ~90° mark (about a quarter turn), which is beyond the actual mechanical stop of the throttle body.

So unless I physically modify the throttle body cam to let the blade open past 90°, I’ll never reach that 4.7V in normal operation.

I’ve tried three different sensors:

The one that came with the Jeep (generic)

A brand-new NTK

A genuine Mopar unit from the dealer (fresh today)

All behave the same — ~0.6V closed, ~2.7V at mechanical WOT, ~4.7V only when rotated past 90°.

So… what am I missing here?
Is this normal for NGC3 TJ PCMs? What voltage do your TPS sensors output at WOT?

Appreciate any insight.

 

[ItchyDong]

Backprobe the signal wire and verify your reading with a multimeter.

Edit: never mind. Just saw you did that.

 

[TEZZA]

What min. and max % values for Throttle Position (SAE) do you see with HP Tuners VCM Scanner?

My 2006 is 11.4% at idle and 79% at full throttle.

 

[CaptainBanana]

What min. and max % values for Throttle Position (SAE) do you see with HP Tuners VCM Scanner?

My 2006 is 11.4% at idle and 79% at full throttle.

12-70% but the voltage is well below what the ECU is expecting.

 

[TEZZA]

70% should be 3.5v
Almost seems like a damaged Throttle body shaft.

 

[CaptainBanana]

70% should be 3.5v
Almost seems like a damaged Throttle body shaft.

70% should be 3.5v
Almost seems like a damaged Throttle body shaft.

Well as it only can rotate a smidge over 90 degrees and the TPS can go well beyond that, this is not the case. This is why I'm hoping someone might be willing to actually put a multimeter to their signal wire and provided voltage value at wide open throttle in volts not percentages via a scan tool.

 

[TEZZA]

The percentages that I quoted are from a log file done with HPTuners VCM Scanner.

The actual voltages read with a digital multimeter at the TPS connector are 0.518v (10.36% of 5v) throttle at idle position and 3.948v (78.96% of 5v) with throttle at full, these voltages are with reference to the negative terminal of the battery and the engine not running.