If you own or are repairing a Jetta
2.5L with code p1340 | 17748 be very careful with your testing and repair. Normally the code is set due to failing timing chain tensioner, broken timing chain guides or stretched timing chains. Occasional we run into this code due to a failing camshaft position sensor. But we ran into a strange one today. This VW
has been to several other repair shops and has had camshaft and crankshaft position sensor replaced for over $600 with out any luck. The Check Engine Light comes right back on and it continued to idle rough. During the testing at the last shop it stopped running all together. If the steps below were followed the customer could have saved a lot of time and money:
P1340/17748 - Crankshaft/Camshaft Position
Signals Out of Sequence
1. With a factory compatible scan tool
A. Select Address Word 01-Engine.
B. Select Function 08-Read Measuring Value Blocks (MVB).
C. Enter Display Group 093. The 4th Display Field will show the timing of the engine. It should read 0 degrees +/- 5 degrees.
D. If the value is outside of specification, a timing chain timing issue is indicated.
2. Special tools T40070 Camshaft Locater and T40069 Crankshaft Locking Pin are required for verification of proper timing and installation.
A.There are no timing marks for the chains. The camshaft locater and the crankshaft locking pin verify the timing.
3. A visual inspection of the timing system will be required to determine why the engine is out of time.
A. Look for damage to guides and tensioners.
B. Look for evidence of lack of lubrication.
C. Look for slack in the timing chains.