TPS Adjustment Procedure

Figure 5 - Wire Routing:

1. If the throttle angle displayed is outside the -1.0 to +1.0 band, measure the TPS signal voltage by connecting a high impedance digital voltmeter to the TPS test point located by the right shock tower. With the meter set to the two volt scale, connect the meter positive lead to CKT 417, dark blue wire, and the negative lead to CKT 476, black/white wire (Figure 5).
With engine still running, loosen the TPS screws just enough to permit the sensor to be rotated. A T-25 torx driver should be used for TPS adjustment. Adjust the TPS so that voltmeter reads .475-.525 volts. Tighten the TPS mounting screws with the sensor in the adjusted position. Recheck ECM data ED01 to be sure that the TPS angle is -1.0 to +1.0.

Important: Do not use excessive force (don't pound or pry) to adjust the TPS or damage to the TPS may occur. The TPS mounting screw must be loosened to perform the adjustment.

Figure 6 - EXTENSION CHECK AND ADJUSTMENT:

ISC Maximum Extension Check and Adjustment

2. With the key "ON", engine "OFF" (extend the ISC motor as described in the jumper harness procedure (Figure 6).
3. With the meter set to the two volt scale, connect the meter positive lead to CKT 417, dark blue wire, and the negative lead to CKT 476, black/white wire. Momentarily apply voltage to extend the ISC motor, noting the voltmeter value with the ISC stopped. Do this multiple times. With the ISC stopped at full extension, one of two voltmeter values will be seen; a high value at the top of the ratchet and a low value at the bottom of the ratchet. Look for the highest TPS voltage, which will be seen when the ISC stops at the top of its ratchet. Stop the ISC when the highest TPS voltage is seen.

4. If the TPS voltage is 1.225-1.325 volts, no adjustment is needed. If the voltage is out of this range, adjust the ISC plunger by turning the plunger in to lower the voltage or out to raise the voltage. Recheck the maximum extension voltage by again applying power to extend the ISC until a maximum TPS voltage is seen.
After All Checks and Adjustments are Completed:

5. Retract the ISC motor plunger halfway before proceeding.

6. Disconnect all test equipment and reconnect the ISC motor connector. Turn the key "OFF" for at least 10 seconds. Start the engine and check the ISC motor for proper operation.

7. The above procedure may have turned on a telltale light or set an ECM or BCM code. Enter diagnostics and clear all stored ECM and BCM codes.
To Retract the ISC Plunger

1. Enter diagnostics and select ECM override ES03 "ISC Motor".

2. Press the cooler button on the CCDIC.

3. Wait approximately 20 seconds for ISC plunger to fully retract.


To Extend the ISC Plunger

1. Connect ISC terminal "D" to 12 volts at the battery or junction block.

2. Connect the ISC terminal "C" to ground until the ISC plunger is partially or fully extended.

Important: If the ISC motor fails to extend, disconnect and reconnect terminal "C" to ground to "bump" the motor from its stalled fully retracted position.

For warranty purposes, use Labor Operation J6358 at .6 hours.