# 17748 - Camshaft Position Sensor (G40) / Engine Speed Sensor (G28) P1340 - 35-00 - Incor. Correlation



## vtraudt (Mar 1, 2010)

Engine swap (AMU, rods, bearing, etc). AEB head. VVT cam chain tensioner (not connected yet).

After engine swap getting code

17748 - Camshaft Position Sensor (G40) / Engine Speed Sensor (G28) 
P1340 - 35-00 - Incor. Correlation

and timing blocks (090-094) show: -99°KW

Removed valve cover and checked cam marks, chain links and cam sprocket mark (lining up with valve cover) and crank pulley TDC mark (lines up).

Engine not running bad (not done a lot of running yet).

What could be the issue?

Cam sensor swapped over from old (well running) engine. 
Not sure what I did with crank (engine speed) sensor, if swapped over or used existing or spare.

Where to start troubleshooting?


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## jimivr6 (Feb 18, 2003)

Your valve timing is off. Check timing marks on chains and timing belt. Not too hard


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## vtraudt (Mar 1, 2010)

jimivr6 said:


> Your valve timing is off. Check timing marks on chains and timing belt. Not too hard


See above: Removed valve cover and checked cam marks (square mark on cam shafts; aligning with cam holder arrow/triangle), chain links (15.5; counting one on the mark, one past the mark = 16) and cam sprocket mark (lining up with valve cover mark) and crank pulley TDC mark (lines up).


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## jimivr6 (Feb 18, 2003)

http://wiki.ross-tech.com/wiki/index.php/17748/P1340/004928


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## vtraudt (Mar 1, 2010)

jimivr6 said:


> http://wiki.ross-tech.com/wiki/index.php/17748/P1340/004928


17748/P1340/004928 - Camshaft Position Sensor (G40) / Engine Speed Sensor (G28): Incor. Correlation

Possible Causes
Timing Belt/Chain incorrectly installed
Timing Chain probably lengthened
Camshaft Position Sensor (G40) faulty
Engine Speed Sensor (G28) faulty

Possible Solutions
- Check Timing Belt/Chain installationDone. May do again, but verified crank at TDC, exhaust cam sprocket mark matches valve cover, cam squares line up with cam holder triangle. 15.5 links. 
- Use Measuring Value Blocks (MVB) to Check Timing Chain: block 090 and 091 show single digit values. nothing in 092 and 093. Other checks?
- Check/Replace Camshaft Position Sensor (G40): will install another one. what are symptoms of faulty G40?
- Check/Replace Engine Speed Sensor (G28): will install another one. what are symptoms of faulty G28? Wouldn't engien speed (RPM) signal be missing or have issues?

Special Notes
- When found in the 1.8T engine, check engine oil pressure. The oil pump pickup may be restricted: Possible that installed VVT cam chain tensioner would cause issues? (AMU and AEB heads do not have VVT, but supposedly can be used; not wired yet). 
- When found in the 1.8T engine (possibly others too), check to make sure the correct G40 is installed (single gap versus 4 gap): done. Had single gap from AEB head still on. Changed to 4 gap. 
On engines with chain driven intake camshaft(s), but belt driven exhaust camshaft(s), verify the number of chain roller links between the intake and exhaust camshafts is correct. Click on thumbnail to enlarge:

http://wiki.ross-tech.com/wiki/images/thumb/1/16/Cam_timing_chains.gif/721px-Cam_timing_chains.gif


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