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I have a 1999 FRC and I need some help with diagnosing this problem. I drove the car during the day with no issues, parked it for a few hours and when I decided to go out again, as soon as I started moving (less than 10 ft), the check engine light and reduced power message came on. The engine idle also started surging. I pulled the codes and the only one is P1518. Did some google-fu and traced the problem to fuse 17 in the hood fuse box, which was blown. Replaced it with a spare 15A fuse and it blew again as soon as ignition is turned on.
The car still cranks/starts normally so I don't think it's a battery voltage issue. From what I read, there doesn't seem to be a ground for the circuit to short to, everything is connected with the TAC module. So it's probably due to chafed wires touching each other. My question is, which harness or wires should I be looking at? I see on the throttle body there are two connectors and the corresponding harness. Is it the one on the driver side or passenger side? Do I have to take the intake manifold off in order to follow it?
I'm referencing the wiring from my 01 and fuse 17 is the ignition feed to the TAC Module which sits below the PCM...there are 2 connectors and C2 which is the 16 pin connector is the one you want...the circuit number is 539 and I don't know what else it feeds from the TAC Module...perhaps the TAC motor which sits on the left side of the throttle body...I'd remove the C2 connector and see if the fuse blows...if it still blows you have a short to ground between the fusebox and the TAC module...you can start there...the wire run looks short between the Module and the fusebox so it might not be that difficult...the TAC module may have an internal short if the fuse does not blow after the C2 connector is removed...I don't see circuit 539 either going to the throttle body or the TPS or APP sensors...probably the first thing I'd do is remove the connector off the TAC motor and turn on the ignition and see if the fuse blows.
Thank you for the reply, currently at work so I can't check right now but that pink wire would be constant battery+ right? Meaning if the fuse is popping, it's touching a ground somewhere? Either another "negative" wire or the frame of the car?
Figured it out - for the people in the future who might have similar problems.
I had a hunch it would be this and as soon as I realized, I slapped myself on the head. Rainwater shorted the connector. It rained after I parked the car outside. Water somehow must've made its way to the connector and shorted it causing the fuse to continuously blow. I was planning on digging deep into the issue today after work but when I went to start the car to double check, the idle surge went away. Cleared the codes, took it for a 20 mile test drive and all is fine. The water must've evaporated and everything is back to normal. Now I need to figure out how to prevent it from getting wet again.
P1518 Code, Fuse 17 Keeps Popping
