2 Open Circuits? P1292 P1531

[Sundevil84]

I am getting two open circuit codes:

17700 MAP CONTROLLED ENGINE COOLING THERMOSTAT (F265): OPEN CIRCUIT
P1292-004 NO SIGNAL/COMMUNICATION

17939 CAMSHAFT TIMING ADJUSTMENT: OPEN CIRCUIT
P1531-004 NO SIGNAL/COMMUNICATION

Is there somewhere that these two circuits overlap that I can check?

I cleared the codes and they keep coming back.

Thanks

[walky_talky20]

Yep. They both share a fuse. It's Fuse #82 - the small 15 amp fuse in the ECU chamber. It should be mounted near the row of relays in there. It probably blew the fuse for a reason. Either the t-stat heater or Cam Adjuster solenoid would likely be to blame. You may want to check the resistance of each quickly before you throw another fuse in.

If the Cam Adjuster (Tensioner) is chinese aftermarket, my gut would say the solenoid is the problem. I had the same issue with an aftermarket piece. It had an intermittent short. In this case you can just change the solenoid itself with a good used Genuine OEM solenoid harvested from a Cam Adjuster that failed mechanically. Due to the reasonably high failure rate of the adjusters, it should not be difficult to located one - especially on this forum.

[Sundevil84]

Yep, found the fuse last night and it was blow. Put a new solenoid in (thinking that was my problem) and a new fuse. Started no CEL, get in this morning and BOOM CEL light comes on. The next thing I'm replacing is the connector at the solenoid. It looked pretty mangled. After that I guess I just run new wire all the way to the ECU.

Again, thanks for the help.

[walky_talky20]

Could be the thermostat heater as well.

[Sundevil84]

I will check that, but my problem started with the Cam Chain tensioner getting a code for an open circuit and the thermostat never made a code. I think I may have done something to the connector when I was fixing the problem with the tensioner.

[walky_talky20]

You could leave the tensioner unplugged for a week. If the fuse stays intact, problem is with the solenoid.

The VVT is not critical, but the t-stat heater is pretty important. Without it the engine temperature will run at the default thermostat temperature with no electronic control. That is about 110C, which is pretty darn hot to be running all the time. With the fuse blown you should eventually get a "error in mapped cooling system" code and the fans will run at maximum speed at all times to try to prevent engine damage.