Ignition System - MIL ON/Misfire DTC's Set/Rough Running
Group: 01Number: 03-02
Date: Feb. 27, 2003
Subject:
Ignition Coil, Misfire Diagnosis
Model(s):
All w / Eng. code (APH, AWD, AWM, AWP, AWV, 2001-->2003
AWW, AXK, BDF, BDP)
Condition
^ MIL light ON/flashing
^ Engine running rough
^ Vehicle exhibits loss of power
^ Diagnostic Trouble Code (DTC) P0300 and any of the following DTCs - P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308 are stored in DTC memory indicating cylinder misfire
Service
With VAS 5051/VAS 5052 Diagnostic tool connected to the vehicle:
- Check misfire recognition.
Misfire recognition, checking:
- Switch ignition ON and start engine.
- From VAS 5051/VAS 5052 Start-up screen, select "Vehicle Self Diagnosis".
- Select vehicle system "01-Engine electronics".
- Select function "02 - Interrogate fault memory".
- Check and print any stored DTC(s).
With DTC memory interrogated:
- Select back arrow <-- on navigation bar.
- Select function "08 - Read data block".
For All engine codes listed
- Input "14" on keypad
- Press "Q" on keypad to confirm.
- Check for misfire recognition and print screen.
- Press the up arrow button to Switch to display group 015 "Checking misfire recognition of individual cylinders 1, 2, 3".
- Check misfire recognition in display fields 1 - 3 (arrows) for cylinders 1, 2, and 3.
Note:
Misfire recognition should be monitored until engine has reached operating temperature.
- Print screen.
For engine codes - APH, AWD, AWM, AWP, AWV, AWW
- Press the up arrow button to Switch to display group 016 "Checking misfire recognition of individual cylinder 4".
- Check misfire recognition in display field (arrow) for cylinder 4.
- Print screen.
- For any misfiring cylinder(s) in question, (misfire counter will be climbing if misfire is currently active).
For engine codes - AXK, BDF, BDP
- Press the up arrow button to Switch to display group 016 "Checking misfire recognition of the individual cylinder(s) 4, 5, 6".
- Check misfire recognition in display field (arrow) for cylinder(s) 4, 5, 6.
- Print screen.
- For any misfiring cylinder(s) in question, (misfire counter will be climbing if misfire is currently active).
For engine code - BDP
- Press the up arrow button to Switch to display group 017 "Checking misfire recognition of the individual cylinder(s) 7, 8".
- Check misfire recognition in display field (arrow) for cylinder(s) 7, 8.
- Print screen.
- For any misfiring cylinder(s) in question, (misfire counter will be climbing if misfire is currently active).
For all engine codes listed:
If misfire counter is active for a single cylinder:
- Replace ignition coil (see note below) for that cylinder see Ignition coil, removing.
If misfire counter is active for more than one cylinder:
- Replace ignition coil (see note below) on cylinder with most misfires, see (Ignition coil, removing).
- Recheck misfire counter again.
If misfire counter is still active for more than one cylinder:
- Contact the Dealer Technician Helpline.
Note:
If faulty ignition coil Part No. is listed in Table, prior to coil replacement:
- Contact the Dealer Technician Helpline.
CAUTION!
Part numbers are for reference only. Always check with your Parts Dept. for the latest parts information.
Ignition coil, removing (engine codes - APH, AWD, AWM, AWP, AWV, AWW)
- Removal Tool T40039 must be used, otherwise coils may be damaged during removal.
Ignition coil, removing (engine code - AXK, BDF)
- Removal Tool T10095A must be used, otherwise coils may be damaged during removal.
Ignition coil, removing (engine code - BDP),
- Removal Tool T10094 must be used, otherwise coils may be damaged during removal.
Ignition coil, installing
- Press coil slowly into cylinder head by hand only.
^ Do not use any object to tap coil into position.
^ Do not twist coil when installing.
With ignition coil replaced:
- Check misfire recognition again.
If misfires are recognized:
- Coil may not be defective, continue to diagnose condition (refer to DTC table in Repair Manual, Group 01 On Board Diagnostic (OBD).
If no misfires are recognized:
- Clear any stored DTCs.
- Set Readiness Code, see Readiness code, generating in Repair Manual, Group 01 - On Board Diagnostic (OBD).
Note:
Print outs of DTCs, Freeze frame data (if used) and measuring value blocks 014, 015, 016 and (017 for W8 Models) must be kept on file and a copy must be included when parts are shipped to the Warranty Test Center.
When procedure applies to vehicles within in the New Vehicle Limited Warranty, use the table.