Lack of Power

Definition: Engine delivers less than expected power. Little or no increase in speed when accelerator pedal is pushed down part-way.

1. Was the "On-Board Diagnostic (OBD) System Check" performed?

[YES] Go to Step 2.
[NO] Go to OBD System Check. Initial Inspection

2. a. Perform a bulletin search.
b. If a bulletin that addresses the symptom is found, correct the condition as instructed in the bulletin.
c. Was a bulletin found that addresses the symptom?

[YES] Verify repair.
[NO] Go to Step 3.

3. Was a visual/physical check performed?

[YES] Go to Step 4.
[NO] Go to Visual/Physical Check. Visual/Physical Check

4. a. Remove and check the air filter element for dirt or restriction.
b. Replace the air filter element if necessary.
c. Was a repair required?

[YES] Verify repair.
[NO] Go to Step 5.

5. a. Check for low fuel pressure.
b. If a problem is found, repair as necessary.
c. Was a problem found?

[YES] Verify repair.
[NO] Go to Step 6.

6. a. Check for water or alcohol contaminated fuel.
b. If a problem is found, repair as necessary.
c. Was a problem found?

[YES] Verify repair.
[NO] Go to Step 7.

7. a. Using a scan tool, monitor the knock sensor (KS) system for excessive spark retard activity.
b. If a problem is found, repair as necessary.
c. Was a problem found?

[YES] Verify repair.
[NO] Go to Step 8.

8. a. Check for proper ignition voltage output with spark tester J 26792 (ST-125).
b. If a problem is found, repair as necessary.
c. Was a problem found?

[YES] Verify repair.
[NO] Go to Step9.

9. a. Remove the spark plugs and check for wet plugs, cracks, wear, improper gap, burned electrodes, or heavy deposits.

NOTE: If spark plugs are gas or oil fouled, the cause of the fouling must be determined before replacing the spark plugs.

b. If a problem is found, repair as necessary.
c. Was a problem found?

[YES] Verify repair.
[NO] Go to Step 10.

10. a. Check the ignition coils for cracks or carbon tracking.
b. If a problem is found, repair as necessary.
c. Was a problem found?

[YES] Verify repair.
[NO] Go to Step 11.

11. a. Check the Powertrain Control Module ([1][2]PCM) for cleanliness, tightness and proper locations.
b. If a problem is found, repair as necessary.
c. Was a problem found?

[YES] Verify repair.
[NO] Go to Step 12.

12. a. Check the exhaust system for possible restriction:
- Inspect the exhaust system for damaged or collapsed pipes.
- Inspect the muffler for heat distress or possible internal failure.
- Check for a possible plugged three-way catalytic converter by checking the exhaust system back pressure.
b. If a problem is found, repair as necessary.
c. Was a problem found?

[YES] Verify repair.
[NO] Go to Step 13.

13. a. Check the torque converter clutch (TCC) for proper operation.
b. If a problem is found, repair as necessary.
c. Was a problem found?

[YES] Verify repair.
[NO] Go to Step 14.

14. a. Check for the following engine mechanical problems.
- Low compression.
- Leaking cylinder head gasket.
- Worn or incorrect camshaft.
- Loose timing belt.
b. If a problem is found, repair as necessary.
c. Was a problem found?

[YES] Verify repair.
[NO] Go to Step 15.

15. a. Review all diagnostic procedures within this table.
b. If all procedures have been completed and no malfunctions have been found, review/inspect the following:
- Visual/physical inspection.
- Scan tool data.
- Freeze Frame data/Failure Records buffer.
- All electrical connections within a suspected circuit and/or system.
c. Was a problem found?

[YES] Verify repair.
[NO] Contact Technical Assistance.