ECU Fuse Keeps Blowing after Trackday - No CEL - TT

JimmyK

Update, still no luck, not even with the Crankshaft Position Sensor or EVAP Canister Vent Control Valve, and no luck with the continuity checks while shaking the harness and the whole car (not out of frustration, I swear).

Here are the updates to the tests performed:

Tests Performed or Planned:

• Condenser
  - Harness under the Intake Manifold.
  - AC is off during event.
  - Inspected with scope and by shaking from where accessible, no shorts.
  
• Ignition Coil 1
  - No tests performed since car idles and revs well, no CELs.
  
• Ignition Coil 2
  - No tests performed since car idles and revs well, no CELs.
  
• Ignition Coil 3
  - No tests performed since car idles and revs well, no CELs.
  
• Ignition Coil 4
  - No tests performed since car idles and revs well, no CELs.
  
• Ignition Coil 5
  - No tests performed since car idles and revs well, no CELs.
  
• Ignition Coil 6
  - No tests performed since car idles and revs well, no CELs.
  
• Intake Valve Timing Control Solenoid Valve Bank 1
  - Violently shook cables while idling.
  
• Intake Valve Timing Control Solenoid Valve Bank 2
  - Violently shook cables while idling.
  
• EVAP Canister Vent Control Valve
  - Disconnected at canister and checked continuity to ECU on pin 2, and to the IPDM on pin 1. No other pins exist, continuity was good even with some shaking.
  - Possible candidate since there's lots of harness spidering its way through the body to get to the canister.
  - OBD reads but no changes, possibly since the pressure isn't changing at idle without sloshing, etc. Less worried about this now since it has continuity at rest.
  
• VVEL Control Module
  - VVEL position sensors and angle advance seem to be working w/OBD monitor, since they change values on idle/throttle.
  
• EVAP Canister Purge Volume Control Solenoid Valve
  - OBD reads % changes under throttle ups in idle that make some sense.
  - Electrical continuity of positive to ECU is good (Pin 21 on ECU), no shorts to ground of ECU or car even with violent shaking.
  
• MAF Bank 1
  - Readings look okay in OBD.
  - Plan to check electrically per FSM.
  - Violently shook cables while idling.
  
• MAF Bank 2
  - Readings look okay in OBD.
  - Plan to check electrically per FSM.
  - Violently shook cables while idling.
  
• Input Speed Sensor (for S-Mode)
  - No tests done or planned, located on transmission.
  - Only one not tested so may check continuity. Don't want to jack car up again for this but might.
  
• Crankshaft Position Sensor (not listed above)
  - Cables look frayed.
  - Violently shook cables while idling.
  - No shorts to power from supply or sensor line, and no shorts to car or ECU ground.
  - Check all pins directly from the ECU to the connector, no shorts to power or ground, neither sensor power or sensor return.
  - Will repair nonetheless.
  
• Continuity Tests
  - Performed continuity tests on all pins coming out of the IPDM (45, 53, 55, 69, 70, all from E7) to the components while shaking the harness up and down the car wherever I possibly could, and no continuity was found so the intermittent short culprit was not located.
  - Components less affected were the EVAP Canister Control Valve and the Input Speed Sensor.