Honda won’t shift out of park: What to check first

What to check when Honda won’t shift out of park

The shift interlock system is designed to prevent shifting out of park unless your foot is on the brake. Plus, if the shift mechanism isn’t fully in the park position, you may not be able to remove the key. Here’s how the system works:

Fuse #10 (20A) in the underhood fuse box provides power to the brake pedal position switch on the red wire. When you apply the brake, power is switched to the ECM/PCM and to connector C304 via the light green wire. The driver’s under-dash relay center sees the brake pedal switch power coming in on the light green wire. At the same time, fuse #17 (7.5) in the driver’s under-dash relay center provides power to the transmission range selector through connector C101. If the transmission range selector is in the PARK or Neutral position, the power will ground at ground point G101. When the ECM/PCM sees that the transmission range selector is grounded (on the blue/black wire), it provides ground to the shift interlock solenoid. Power to the shift interlock solenoid is provided by Fuse #5 in the driver’s under-dash relay center.

To diagnose a Honda won’t shift out of park condition

Check fuses #10, 17, and 5 first. Then check for ground on the black wire at the shift interlock solenoid with the key in the RUN position and foot on the brake. If you don’t see ground, the ECM/PCM isn’t providing ground. If you do find ground, then check the operation of the shift interlock solenoid in the shift console. Next, check for ground on the blue/black wire B14 at the ECM/PCM with transmission in park or neutral, key in RUN position, and foot on the brake. If you don’t see ground, check for ground on the black wire at the transmission range selector with thr transmission in park or neutral and foot on the brake. If you don’t see ground, then check for a broken or open on the blue/black wire between the C101 junction connection and the ECM/PCM behind the engine near the firewall.

©, 2016 Rick Muscoplat