| 1 |
Was the "On-Board Diagnostic (OBDII) System Check" performed? |
- |
Go to Step 2 |
Go to On-Board Diagnostic (OBD-II) System Check |
| 2 |
- Perform a bulletin search.
- If a bulletin that addresses the symptom is found, correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom? |
- |
Verify repair |
Go to Step 3 |
| 3 |
Was a visual/physical check performed? |
- |
Go to Step 4 |
Go to VISUAL/PHYSICAL CHECK |
| 4 |
If Tech 2 readings are normal
and there are no engine mechanical faults, fill the fuel tank with a known quality gasoline that has a minimum octane rating of 87 and re-evaluate the vehicle performance.
Is detonation present? |
- |
Go to Step 5 |
Verify repair |
| 5 |
- Check the transmission circuit.
Use a Tech 2 and be sure the Tech 2 indicates that the vehicle is in drive with the gear selector in drive or overdrive.
- If a problem is found, diagnose and repair the transmission range switch as necessary (refer to TRANSMISSION CONTROL SYSTEM
).
Was a problem found? |
- |
Verify repair |
Go to Step 6 |
| 6 |
- Check TCC operation. (Refer to TRANSMISSION CONTROL SYSTEM
).
- If a problem is found, repair as necessary.
Was a problem found? |
- |
Verify repair |
Go to Step 7 |
| 7 |
- Check for obvious overheating problems:
- Low engine coolant.
- Restricted air flow to radiator, or restricted water flow through radiator.
- Correct coolant solution should be a 50/50 mix of approved antifreeze/coolant and water. Refer to ENGINE COOLING (6VE1-DI 3.5L)
.
- VVT System
- Knock sensor
- IAT sensor
- If a problem is found, repair as necessary.
Was a problem found? |
- |
Verify repair |
Go to Step 8 |
| 8 |
- Disconnect the ignition coil.
Is the action complete? |
- |
Go to Step 9 |
- |
| 9 |
Check the following items;
- Ignition coil and ignition coil circuit.
- Ignition coil ground circuit for a poor connection.
- If a problem is found, repair wiring harness as necessary.
Was a problem found? |
- |
Verify repair |
Go to Step 10 |
| 10 |
Replace the Ignition coil.
Is the action complete? |
- |
Verify repair |
Go to Step 11 |
| 11 |
- Check for VIM.
- If a problem is found, repair as necessary.
Was a problem found? |
- |
Verify repair |
Go to Step 12 |
| 12 |
- Check fuel pressure. Refer to Fuel System Check (High Pressure Line)
or Fuel System Check (Low Pressure Line)
.
- If a problem is found, repair as necessary.
Was a problem found? |
- |
Verify repair |
Go to Step 13 |
| 13 |
- Check items that can cause an engine to run lean (long term fuel trim significantly in the positive range). For a lean condition, Refer to Diagnostic Aids
in DTC P0171 Diagnostic Support.
- If a problem is found, repair as necessary.
Was a problem found? |
- |
Verify repair |
Go to Step 14 |
| 14 |
- Spark plugs for proper heat range. Refer to IGNITION SYSTEM
.
- If incorrect spark plugs are installed, replace spark plugs as necessary.
Did any spark plugs require replacement? |
- |
Verify repair |
Go to Step 15 |
| 15 |
- Remove excessive carbon buildup with a top engine cleaner. Refer to instructions on the top engine cleaner can.
- Re -evaluate vehicle performance.
Is detonation still present? |
- |
Go to Step 16 |
Verify repair |
| 16 |
- Check for an engine mechanical problem. Perform a cylinder compression check. Refer to ENGINE MECHANICAL (6VE1-DI - 3.5L)
.
- If a problem is found, repair as necessary.
Was a problem found? |
- |
Verify repair |
Go to Step 17 |
| 17 |
- Review all diagnostic procedures within this table.
- If all procedures have been completed and no malfunctions have been found, review/inspect the following:
- Visual/physical inspection
- Tech 2 data
- Freeze Frame data/Failure Records buffer
- All electrical connections within a suspected circuit and/or system.
- If a problem is found, repair as necessary.
Was a problem found? |
- |
- |
Contact Technical Assistance |