Corvette Trouble Codes: Identifying and Solving the Problems

'86-'89 Corvettes use a powered fuse link and connector that supplies power to the fuel pump and MAF relays behind the battery. The '85 Corvettes do not use relays for the MAF, but instead use a module next to the ECM. This module rarely goes bad; but to check the module on '85 Corvettes, look for 12 volts at connection E on the MAF with the engine running. Then, run the engine for at least 5 minutes, turn off the key, and check for 12 volts at connection D (MAF burn-off). The powered fuse link is a common cause of intermittent MAF codes. Check the connection and wire for a possible open circuit.

The oil-pressure switch is another possible cause of intermittent MAF codes. If the engine feels as if it has an intermittent hiccup with a fuel pump and MAF code set, the oil-pressure sensor would be the place to start. If the switch is bad, the engine tries to start because power to the pump at startup is fed through the ECM's fuel-pump-relay drive (connection A1).

Over the years, some changes were made to the relays for the MAF. The '86 and early '87 relay for MAF power was PN 100067925; the burn-off relay was PN 10094701.