Tech Tips (by ALLDATA): Electrical ‘Gremlins’ plague GMC Savana

TECH TIPS (courtesy of ALLDATA)

Mileage: 159,003

Problem: The customer complained of intermittent problems with the head lamps going off and on by themselves and fuel pump staying on, even with the key off. There were other random, intermittent electrical problems too. The malfunction indicator lamp (MIL) was on.


The tech connected a scan tool and found a DTC P0088 – Fuel Rail Pressure (FRP) Too High. This code sets if the following conditions are met:

  • The actual FRP is more than 20 MPa (2,900 psi) above the desired FRP, or
  • The actual FRP is more than 1,89 MPa (27,412 psi)

Often, when a P0088 DTC sets, it can cause a fuel knock and smoke condition. There may or may not be any drivability concerns. The code can also set if the FRP regulator is sticking. The tech checked for these other symptoms and found none.

Next, the tech inspected the under-hood fuse box and noticed the cover was cracked and missing a piece. He removed the cover and found the fuse box was full of corrosion. Unfortunately, the customer couldn’t afford a new fuse box.


Confirmed Repair: A good, thorough cleaning with baking soda removed all the corrosion. The tech double-checked every fuse connector – no corrosion and the fuses all fit tight – and he repaired the crack in the fuse cover with silicone sealant. The gremlins were eradicated, and all the electrical problems were fixed!