1999 Chevrolet Tahoe P1345 Code: What It Means and How to Fix It

The P1345 code relates to a variation in signal between the Crankshaft Position (CKP) and Camshaft Position (CMP) sensors. This indicates that the Powertrain Control Module (PCM) is detecting inconsistent timing between the crankshaft and camshaft. Possible causes include: a faulty CKP or CMP sensor, wear on the distributor gear teeth, or an improperly reinstalled distributor—especially after work like replacing intake manifold gaskets. In many cases, this code appears after the distributor has been removed. The camshaft position sensor is typically located within the distributor assembly (on 1999 Tahoe engines), while the CKP sensor is usually mounted on the engine block or crankshaft pulley. The timing must be precisely set to ensure proper operation. For optimal performance, the system should maintain a timing variation of +/-2 degrees from zero at idle or 1000 RPM—this specification may vary slightly by model year. What is the current mileage on your engine? Any recent work done on the intake or distributor? Best of luck—please update us if you find a solution. —Jeff

Thanks for the detailed response! I have approximately 113,000 miles on my engine. The distributor was recently removed during an intake manifold gasket replacement. Where are the CKP and CMP sensors located exactly?

If the distributor was recently removed, that's likely the root cause—either it wasn't reinstalled correctly or the timing is off due to gear wear. On a 1999 Tahoe, the camshaft position sensor is integrated into the distributor assembly, and the CKP sensor is typically located on the engine block near the crankshaft pulley. The key issue here is that the distributor must be reinstalled precisely with proper alignment—especially ensuring the rotor points to the correct terminal (number one cylinder). A single tooth misalignment can go unnoticed because the engine may still run, but it will trigger P1345 due to timing inaccuracies. You’ll likely need a scan tool to perform a 'timing relearn' after correcting the physical alignment.

The distributor was removed for a manifold gasket replacement. Could I simply reinstall it, align the rotor with terminal one on the cap, and then drive the truck to resolve the issue?

Yes—as long as you correctly align the rotor with the number one terminal and ensure you're not 180 degrees out of phase, your engine should run properly. If it's currently running fine, you might already be close to correct timing. However, a scan tool is still recommended to verify current readings and perform a relearn procedure if needed. Most modern systems (like in the 1999 Tahoe) don’t allow simple manual adjustments—timing must be reset via software after physical realignment. Your scan tool should show your current actual timing value. It’s not as straightforward as older mechanical setups, but with proper attention to detail, it can often be resolved. Keep us posted! —Jeff

I recently replaced the head gasket on my 1997 Tahoe and encountered the same P1345 issue. After some trial and error, I realized I had misaligned the distributor gear by one tooth—either direction. Once I corrected that alignment, the problem went away. Because the engine’s ECU controls timing digitally, being off by just one tooth can go undetected during operation. The truck will still run, but it may trigger this code due to sensor mismatch. This is a common issue after mechanical work involving the distributor or intake components—always double-check alignment before reinstallation. Good luck with your fix!