Overview - Camshaft Timing Chain, Engine Codes CHHB, CNTA, CXCA, CXDA, CXCB, CXDB And DKFA
After performing work on the chain drive the adaptation value in the engine control module must be adapted. To do so, turn on the ignition and select the following menu items on the Vehicle Diagnostic Tester:
01 - Engine Electronics
Guided Functions
01 - Adaptation after repair work on the chain drive
- Bolt
- 4 Nm +90°
- Replace after removing.
- Chain Tensioner
- Is under tension
- Secure using the Locking Tool: T40267 before removing
- Timing Chain Tensioning Rail
- Guide Pin
- 20 Nm
- Bolt
- Adapter Sleeve
- Depending on the version, not present on every bearing bracket
- Pulled into the cylinder head with the bolt
- Control Valves
- 35 Nm
- Left-hand thread
- Depending on the version, remove using the Assembly Tool: T10352/2 or Assembly Tool: T10352/4 .
- Checking. Refer to Fig 2.
- Bearing Bracket
- Tightening specification and sequence for bearing bracket with steel bolts. Refer to Fig 4.
- Tightening specification and sequence for bearing bracket with aluminum bolts. Refer to Fig 5.
- Assembly instructions. Refer to Fig 3.
- Depending on the version with adapter sleeve. Refer to the Parts Information for the allocation.
- Camshaft Timing Chain Guide Rail
- Camshaft Housing
- Camshaft Timing Chain
- Removing and Installing. Refer to CAMSHAFT TIMING CHAIN, REMOVING AND INSTALLING .
- Before removing, mark the running direction with paint
- Camshaft Timing Chain Guide Rail
- Guide Pin
- 20 Nm
- Three Stage Chain Sprocket
- Crankshaft
- Installation position. Refer to Fig 6.
Checking the Control Valve
-- The piston -1- must be pushed in approximately 3 mm against the spring force. It must not become stuck while doing so.
Bearing Bracket - Assembly Instructions
If a new bearing bracket -3- with adapter sleeve -4- should be installed, it must be checked before installing the bearing bracket in the hole -arrow- in the cylinder head -1-.
If the hole -arrow- is not designed for using the adapter sleeve -4- the adapter sleeve must be removed from the bearing bracket. For this hole the short bolt -2- should be used. Refer to the Parts Information for the correct bolt.
Tightening Specification and Sequence for Bearing Bracket with Steel Bolts
If an adapter sleeve is installed, this will be moved with the bolt -1- in the cylinder head.
-- Tighten the bolts in the steps shown in the sequence:
| Step | Bolts | Tightening Specifications |
|---|---|---|
| 1. | -1- | 3 Nm |
| 2. | -1 to 6- | 9 Nm |
Tightening Specification and Sequence for Bearing Bracket with Aluminum Bolts
-- Tighten the bolts in the shown sequence -1 to 6- in steps:
| Step | Bolts | Tightening Specification/Additional Turn |
|---|---|---|
| 1. | -1 through 6- | 4 Nm |
| 2. | -1 through 6- | 180° additional turn |
Three Stage Chain Sprocket - Installed Position
- Both surfaces -arrows- must align.