Diagnosis & Repair
- Access ECM behind right kick panel. Turn ignition on. Apply vacuum to throttle opener. Backprobing ECM harness connector, measure voltage between terminals VTA and E2. See Figure, Figure and Figure. Voltage should be .3-.8 volt with throttle fully closed and 3.2-4.9 volts with throttle fully open (WOT).
- Backprobing ECM harness connector, measure voltage between terminals IDL and E2. See Figure, Figure and Figure. Voltage should be below 3.0 volts with throttle fully closed and 9-14 volts with throttle fully open (WOT).
- Voltage measurements taken in steps 1) and 2) should increase steadily in proportion to throttle valve opening angle. If voltage measured is within specification, check appropriate connections. Problem may be intermittent. If voltage is NOT within specification, go to next step.
- Disconnect TPS harness connector. Using ohmmeter, measure resistance between component terminals VTA and E2. See Fig 1. Resistance should be .2-5.7 k/ohms with throttle fully closed and 2.0-10.2 k/ohms with throttle fully open (WOT).
- Measure resistance between terminals IDL and E2. See Fig 1. Resistance should be less than 2.3 k/ohms with throttle fully closed and infinite resistance with throttle fully open (WOT).
- Resistance measurements taken in steps 4) and 5) should increase steadily in proportion to throttle valve opening angle. If resistance measured is within specification, go to next step. If resistance is NOT within specification, check TPS adjustment. See the SYSTEM/COMPONENT TESTS - 2.4L
article. Adjust as necessary. If adjustment is okay, replace TPS.
- Inspect circuits between TPS and ECM for opens or shorts. Repair as needed. If circuits are okay, replace ECM and retest.
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