E022

ECM Code E022:

DFI Sensor Circuit:

DESCRIPTION:

The Throttle Position Sensor (TPS) is a three wire sensor or potentiometer with a five volt reference input from the ECM to the sensor (CKT 474), a reference ground from the ECM to the sensor (CKT 476) and an output signal (CKT 417) from the sensor to the ECM. The output signal is a D.C. voltage that varies with throttle angle. At low throttle angle, the TPS signal voltage is low (about .5 volts at minimum air setting) and at high throttle angles, the TPS signal voltage is high (about 4.5 volts at wide open throttle. Code E022 is set when the ECM sees a throttle angle that is out of limits low (low TPS voltage) with engine running at idle or faster. The code is designed to detect a TPS signal (CKT 417) open to ECM pin D7.

TEST CONDITIONS:

1. Engine speed greater than or equal to 600 RPM.

FAILURE CONDITIONS:

TPS value less than -5 degrees (TPS parameter reads -10 to -6 degrees) for 1.5 seconds.

ACTION TAKEN:

1. ECM turns on "SERVICE ENGINE SOON" telltale.
2. ECM commands BCM to display "SERVICE SOON" message on CCDIC.
3. ECM uses 12 degrees for TPS value with ISC throttle Switch open, and 6 degrees for TPS value when ISC throttle switch closes.
4. ECM stops using TPS to control ISC - uses engine speed for all ISC calculations.

NOTES ON FAULT TREE:

1. Jumpering 5 volts to TPS signal to see if the ECM parameter will respond to high signal voltage oil TPS inputs (CKT 417).

2. Checking for TPS reference (CKT 474) open/shorted.

3. Checking for TPS signal (CKT 417) grounded.

4. Fault is most likely at the ECM connector or ECM. Before replacing the ECM, perform the "ECM Replacement Check", CHART C-1.

NOTE ON INTERMITTENTS:

If a code E022 is intermittent, manipulate related wiring while observing ECM parameter EDO1. Cycle the TPS through its travel and tap on the TPS with a pencil or pocket screwdriver to test for intermittent TPS. If the fault is induced, the parameter will jump to -6 or less. If wiring and connectors check out OK, substitute a known good TPS sensor and retest.
Review the snapshot data parameters stored with this code to verify failure condition. If the failure condition is verified, check and repair intermittent wiring connection, or sensor.