M56 Service Procedure
M56 Service ProcedureWARNING:
Never open the cooling system when the engine is hot. Serious burns may occur from hot high-pressure engine coolant escaping from the cooling system.
NOTE:
During this procedure you will remove several similar size bolts with different lengths. It is important to keep track of which length bolt goes in which location.
1. Write down the radio station presets.
2. Release fuel system pressure as follows:
a. Turn the ignition ON.
b. Connect CONSULT-III or CONSULT-III plus.
c. Perform FUEL PRESSURE RELEASE in ENGINE WORK SUPPORT.
d. Start engine.
e. After engine stalls, crank it two or three times to release all fuel pressure.
f. Turn ignition OFF, disconnect CONSULT.
3. Remove the battery cover.
4. Disconnect both battery cables; negative cable first.
5. Remove the engine cover.
a. Remove 2 bolts.
b. Use hand pressure to carefully pull UP at the mounting locations shown in Figure 1m.
6. Remove air intake tubes; both sides:
a. Loosen spring clamps and disconnect hoses from air intake tubes.
b. Loosen clamps at each end of the air intake tubes.
c. Remove air intake tubes from the engine.
7. Remove engine cover brackets.
^ Each bracket is held on with 1 bolt.
8. Remove bolts securing coolant pipe.
WARNING:
Do not loosen or remove spring clamps on coolant hoses. Hot coolant may come out if the engine is hot.
9. Remove both throttle bodies:
^ Driver side shown; passenger side is a mirror image.
^ Leave coolant hoses connected to the throttle bodies.
WARNING:
Do not loosen or remove spring clamps on coolant hoses. Hot coolant may come out.
a. Disconnect electrical connectors from the throttle bodies.
b. Remove the mounting bolts (4 on each Figure 5m throttle body).
c. Pull the throttle body away from the intake manifold and place it to the side, away from the manifold.
d. Cover the intake manifold openings with clean rags to prevent debris entry.
10. Disconnect EVAP solenoid electrical connector (see Figure 6m).
11. Disconnect EVAP service port hose and position hose out of the way (see Figure 6m):
a. Loosen spring clamp and disconnect hose from EVAP solenoid.
b. Use a medium flat blade screwdriver to carefully push UP and remove EVAP valve from its mounting bracket.
c. Position service port hose out of the way.
12. Disconnect manifold absolute pressure sensor electrical connector.
NOTE:
The manifold absolute pressure sensor is under the EVAP Solenoid (see Figures 6m and 7m).
13. Remove 2 harness bracket mounting bolts shown in Figure 8m; passenger side of engine.
14. Disconnect the positive crankcase ventilation (PCV) hoses from the intake manifold; both sides (see Figure 9m).
a. Loosen spring clamps.
b. Disconnect hoses and position them out of the way.
15. Disconnect main harness from the intake manifold bracket as follows:
a. Remove 2 bolts securing main harness to bracket.
b. On the bottom of the main harness, use needle-nose pliers to pinch and release 2 clips.
16. By hand, remove the fuel pump foam insulator shown in Figure 12m.
17. Remove 1 bolt securing coolant pipe to rear of intake manifold; driver side.
18. Remove 10 bolts securing the intake manifold to the engine (see Figure 14m).
19. Lift the front of the intake manifold UP and pull it forward approximately 4 inches.
NOTE:
With the manifold in this position you can access the brake booster vacuum hose and harness clip attached to the rear of the manifold.
20. Disconnect the brake booster vacuum hose from the intake manifold:
a. Look behind the intake manifold (see Figures 15m and 16m) and locate the hose.
b. Loosen the spring clamp and disconnect the hose.
21. Disconnect or cut the harness tie-clip at the back of the intake manifold:
a. Look behind the intake manifold (see Figure 15m and 17m) and locate the tie-clip.
b. Disconnect or cut the tie-clip.
22. Remove the intake manifold from the engine and place clean rags over the intake ports to prevent debris from entering the engine.
23. At the back of the intake manifold, remove the harness tie-clip.
NOTE:
A new tie wrap will be installed on the harness before installing the intake manifold.
24. Remove insulators covering the fuel rails.
25. Disconnect fuel rail pressure sensor electrical connector:
26. Carefully inspect the area around the fuel rail pressure sensor for any evidence of leakage.
No evidence of leaking - go to the next step.
Evidence of leaking is found:
a. Remove the fuel rail pressure sensor.
b. Replace the gasket (sealing washer).
c. Reinstall the fuel rail pressure sensor.
d. Go to the next step.
27. Torque the fuel rail pressure sensor as follows:
a. Measure the length of your torque wrench between the center of the handle and the center of the square drive as shown in Figure 21m.
b. Set the torque wrench using the chart above.
c. Attach special tool to J-50991 to your torque wrench - use an extension if needed.
d. Torque the sensor to the specified torque.
NOTE:
Make sure to keep the extension tool (J-50991) straight (in line) with the torque wrench as shown in Figure 23m.
28. Re-connect the fuel rail pressure sensor electrical connector.
IMPORTANT:
You can not see or connect this connector after the intake manifold is installed.
Tighten Additional Fuel Rail Connections Before Reassembly
29. Torque the bolts shown in Figure 24m:
11 N-m (1.1 Kg-m, 97 in-lb)
30. Torque the flange nuts shown in Figure 25m:
33.4 N-m (3.4 Kg-m, 25 ft-lb)
^ Use a short 19 mm crowfoot wrench.
31. Reinstall insulators covering the fuel rails.
Reassembly
32. Install a new tie-clip on the harness at the center rear to the engine.
^ Tie-clip P/N 24225-C9901.
^ Look for witness marks on the wiring harness made by the original tie-clip.
^ Make sure the mounting clip is facing toward the intake manifold.
NOTE:
This tie-clip will replace the one that was cut off in step 21 above.
33. Install new intake manifold gaskets.
NOTE:
^ For vehicles in dealer inventory (less than 125 miles), new gaskets are not needed.
^ Clean and inspect the old gaskets. Make sure gaskets are not torn or cut and they are installed properly.
34. Reinstall all parts removed in reverse order.
Reassembly Tips / Information
^ Attach wire harness on passenger side of intake manifold (see Figure 8m) before installing intake manifold bolts. This will prevent harness from being pinched under the intake manifold.
^ Start intake manifold bolts by hand and then tighten in the order shown in Figure 29m:
Torque to 10.8 N-m (1.1 Kg-m, 96 in-lb).
^ Install new throttle body gaskets.
NOTE:
For vehicles in dealer inventory (less than 125 miles), new throttle body gaskets are not needed. Clean and inspect the old gaskets. Make sure gaskets are not torn or cut and they are installed properly.
^ Start throttle body bolts by hand and then torque to 10 N-m (1.0 Kg-m, 89 in-lb).
^ Make sure engine cover brackets are installed on the correct side.
^ One is marked with an "L" indicating Left side (driver side).
^ One is marked with an "R" indicating Right side (passenger side).
^ Before installing the engine cover, check the following items:
Wiring harness tie-clip and brake booster vacuum hose secured
Main harness secured to intake manifold
Rear coolant pipe secured to intake manifold
EVAP hoses, EVAP solenoid connector, and manifold absolute pressure sensor connector secure
Throttle body harness connectors secured
Driver side and passenger side Intake air tube clamps secured
Front coolant pipe secured to intake manifold
Fuel pump foam insulator installed
Engine cover brackets secured to intake manifold
EVAP valve secured
35. Reconnect battery cables, positive cable first, and install the battery cover.
36. Keep foot off of the brake and cycle ignition OFF > ON, wait 3 seconds, > OFF. Repeat 3 times to build pressure in the fuel system.
37. Start the engine and make sure no warning lights are ON, and confirm the engine will rev past 4000 rpm.
38. Reset the clock and radio station presets.
39. Reinitialize each auto-up power window as follows:
a. Turn ignition ON.
b. Open window all the way DOWN.
c. Pull all the way UP on the switch and HOLD (close the window completely), continue to HOLD for 4 seconds after window is completely closed.
d. Confirm auto up/down operates correctly.
40. Inform the customer they will need to reset their ADP (Automatic Drive Positioner).