P2135

[frey.199]

I've been throwing this code the last few days and it's kicking it straight into limp mode. When I first experienced it, it was when I would give it a hard acceleration into higher RPMs. Now it's to the point where it will just kick into limp mode at idle and throw the code.

The TB I have is practically new, maybe a year old and is GM non aftermarket. So my next guess would be the the pedal needs replaced. As far as this code goes, can anyone else think of something that it might be other than replacing the pedal? Just checking and have browsed the forum and everything seems to lead to TB or pedal.

[Greenhornet2]

Most likely the throttle body. If not ECM or wiring issue

1. Ignition OFF, disconnect the harness connector at the Q38 throttle body.
2. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 Ω between the low reference circuit terminal C and ground.
3. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.
4. Ignition ON, test for 4.8–5.2 V between the 5 V reference circuit terminal E and ground.
5. If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.

• If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.

1. Test for less than 1 V between the TP sensor 1 signal circuit terminal D and ground.
2. If greater than specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
3. Install a 3 A fused jumper wire between TP sensor 1 signal circuit terminal D and the 5-volt reference circuit terminal E. Verify the scan tool TP sensor 1 voltage parameter is greater than 4.8 V.
4. If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
5. Test for 4.8–5.2 V between the TP sensor 2 signal circuit terminal F and ground.
6. If less than specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.

• If greater than specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.

1. If all circuits and connections test normal, replace the Q38 throttle body assembly.

[frey.199]

Originally Posted by Greenhornet2

Most likely the throttle body. If not ECM or wiring issue

1. Ignition OFF, disconnect the harness connector at the Q38 throttle body.
2. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 Ω between the low reference circuit terminal C and ground.
3. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.
4. Ignition ON, test for 4.8–5.2 V between the 5 V reference circuit terminal E and ground.
5. If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.

• If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.

1. Test for less than 1 V between the TP sensor 1 signal circuit terminal D and ground.
2. If greater than specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
3. Install a 3 A fused jumper wire between TP sensor 1 signal circuit terminal D and the 5-volt reference circuit terminal E. Verify the scan tool TP sensor 1 voltage parameter is greater than 4.8 V.
4. If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
5. Test for 4.8–5.2 V between the TP sensor 2 signal circuit terminal F and ground.
6. If less than specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.

• If greater than specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.

1. If all circuits and connections test normal, replace the Q38 throttle body assembly.

Where did you happen to get this? Do you know if their is a diagram where its referencing terminal C, terminal E, etc?

[Greenhornet2]

if you take the throttle body connector off and looks at the pins with the locking tab on top the top right pin is pin A the top left is C the bottom right is D the bottom left is f
Pin # COLOR CKT Function

A 0.8 BN 582 TAC Motor Control– 2
B 0.8 YE 581 TAC Motor Control– 1
C 0.5 TN 2752 Low Reference
D 0.5 D-GN 485 TP Sensor 1 Signal
E 0.5 GY 2701 5-Volt Reference 2
F 0.5 PU 486 TP Sensor 2 Signal

[Greenhornet2]

It's quite likely the throttle body unless you have a mouse problem. Brand new throttle bodies can have issues, they are finicky contraptions.

[frey.199]

Ok, i'll try to run some ohm tests on it after work. Thanks

[frey.199]

Originally Posted by Greenhornet2

It's quite likely the throttle body unless you have a mouse problem. Brand new throttle bodies can have issues, they are finicky contraptions.

Do you happen to know if I can test my pedal the same way too?

[frey.199]

Originally Posted by Greenhornet2

It's quite likely the throttle body unless you have a mouse problem. Brand new throttle bodies can have issues, they are finicky contraptions.

So I ran 4 different tests on the TB. When testing TSP 2, I push in the throttle and open the plate, numbers look good. As I'm releasing the it back to idle position, as the number change, it goes to OL for a split second and then back to numbers again. Almost like their is a small glitch as the throttle closes. I tested the same for TSP 1, but the OL never comes up. I also tested the actuator motor, terminal A and B and I get 1.9ohms. Was told between 2 and 15 is good. Thoughts?

[Greenhornet2]

TSP2 going OL is the issue, throttle body