6.2L Diesel Heavy Duty (VIN J)

Remove air cleaner assembly and vacuum hoses. Disconnect TP sensor connector and install jumper wires between TP sensor and TP sensor harness connector. Turn ignition on, engine off.
Using a DVOM, measure and record voltage between TP sensor connector terminals "A" and "C". This is the TP sensor reference voltage. Perform the following calculations:
- Reference voltage x 0.33 = Desired TP sensor voltage setting. Record desired TP sensor voltage setting.
Insert a .646" Gauge Block (J-33043-2) between gauge boss on pump and WOT stop screw on throttle lever. See Fig 1 and Fig 2 . Rotate throttle lever towards the WOT position, so gauge block is held firmly in place.
Measure voltage between TP sensor terminals "B" and "C". This is TP sensor voltage. Voltage must be within 1 percent of the desired TP sensor voltage setting from step 2). If TP sensor voltage is within tolerance, proceed to step 6). If TP sensor voltage setting is not within tolerance, go to next step.
To adjust TP sensor, loosen TP sensor mounting screws and rotate TP sensor until desired TP sensor voltage is obtained. Tighten TP sensor mounting screws and recheck voltage reading. Replace TP sensor assembly, if adjustment is not possible.
NOTE: Switch point must be set only while rotating TP sensor body in clockwise direction.
Release throttle lever and allow lever to return to idle position. Open throttle lever back against gauge block and check if TP sensor voltage is within TP sensor reference voltage, see step 2). If reading is not within tolerance, replace TP sensor assembly.
Turn ignition off. Remove gauge block, jumper from TP sensor and wiring harness, and reconnect TP sensor harness connector. Reinstall air cleaner assembly.

Fig 1: Adjusting TP Sensor (6.2L - VIN C & J) (1 Of 2)

Courtesy of GENERAL MOTORS CORP.

Fig 2: Adjusting TP Sensor (6.2L - VIN C & J) (2 Of 2)

Courtesy of GENERAL MOTORS CORP.