A/T - E40D Overdrive OFF Light Cycles with Brake Pedal
TECHNICAL BULLETIN # 247TRANSMISSION: E4OD
SUBJECT: "Overdrive Off" light cycles with brake pedal
APPLICATION: Ford
DATE: Jan 1994
E4OD Diesel "Overdrive Off" Light Cycles With Brake Pedal
A condition where the "overdrive off" light cycles on and off while the brake pedal is pressed, is usually caused by a short between the brake on/off (BOO) switch and the overdrive cancel switch (OCS) circuits. Some diesel trucks have a harness connector that is located under or near the battery.
The BOO and OCS circuits use this connection. It is not uncommon to find that the connector or wires to the connector have corroded due to exposure to battery acid. This has been known to cause a short circuit in the connector or wires going to the connector. In most cases, the connector can be cleaned to fix this condition.