Step | Action | Values | Yes | No |
|---|---|---|---|---|
|
Important: Before diagnosing the symptom, check service bulletins for updates. DEFINITION: The engine runs unevenly at idle. If the condition is bad enough, the vehicle may shake. Also, the idle varies in RPM, called hunting. Either condition may be severe enough to cause stalling. The engine idles at incorrect idle speed. | ||||
1 | Were the Preliminary Checks performed? | -- | Go to Step 2 | |
2 |
Does the O2S sensor change quickly from rich to lean at the different throttle positions? | -- | Go to Step 5 | Go to Step 3 |
3 | Inspect the O2S sensor for contamination from fuel or improper use of room temperature vulcanizing (RTV) sealant. Is the O2S sensor contaminated? | -- | Go to Step 4 | Go to Step 5 |
4 | Replace the contaminated O2S sensor as needed. Did you complete the replacement? | -- | System OK | -- |
5 |
Is the TP sensor voltage within the specified range? | 0.4-0.8 V | Go to Step 6 | Go to DTC P0123 |
6 |
Does the ECT temperature reading differ from the ambient temperature greater than the value specified? | 3°C (5°F) | Go to Step 7 | Go to Step 9 |
7 | Measure for high resistance in the ECT sensor circuit or the sensor itself. Is a repair necessary? | -- | Go to Step 8 | Go to Step 9 |
8 | Replace the ECT sensor or repair the circuit as needed. Did you complete the repair? | -- | System OK | -- |
9 | Inspect the manifold absolute pressure (MAP) sensor for response and accuracy. Is a repair necessary? | -- | Go to Step 10 | Go to Step 11 |
10 | Replace the MAP sensor or repair the MAP sensor circuit as needed. Did you complete the repair? | -- | System OK | -- |
11 |
Is the fuel trim reading within the specified range? | -20% to +25% | Go to Step 14 | Go to Step 12 |
12 | Is the fuel trim reading less than the value specified? | -20% | Go to DTC P0132 | Go to Step 13 |
13 | Is the fuel trim reading greater than the value specified? | 25% | Go to DTC P0131 | -- |
14 |
Does the test light blink for all of the fuel injectors? | -- | Go to Step 16 | Go to Step 15 |
15 |
Did you complete the repair? | -- | System OK | -- |
16 | Measure the resistance of each of the fuel injectors. The resistance will increase slightly at higher temperatures. Is the resistance within the specified range? | 11.6-12.4 ohms | Go to Step 18 | Go to Step 17 |
17 | Replace any fuel injectors with a resistance that is out of specifications. Did you complete the replacement? | -- | System OK | -- |
18 | Perform an injector balance test. Refer to Fuel Injector Balance Test with Special Tool . Is a repair necessary? | -- | Go to Step 19 | Go to Step 20 |
19 | Replace any leaking or restricted fuel injectors. Did you complete the replacement? | -- | System OK | -- |
20 |
Is a repair necessary? | -- | Go to Step 21 | Go to Step 22 |
21 | Replace the fuel pressure regulator as needed. Did you complete the replacement? | -- | System OK | -- |
22 |
Did you find and correct the condition? | -- | Go to Step 23 | Go to Step 24 |
23 | Repair or replace any ignition system components as needed. Did you complete the repair? | -- | System OK | -- |
24 |
Is a repair necessary? | -- | Go to Step 25 | Go to Step 26 |
25 | Repair or replace any components as needed. Did you complete the repair? | -- | System OK | -- |
26 |
Did you find and correct the condition? | -- | Go to Step 27 | Go to Step 28 |
27 | Repair or replace any components as needed. Did you complete the repair? | -- | System OK | -- |
28 |
Did you find and correct the condition? | -- | System OK | -- |
