Faulty Signal

ECM-91DF STOP (BRAKE) LAMP SWITCH, FAULTY SIGNAL
FAULTY SIGNAL

General
This diagnostic trouble code (DTC) can be caused by CAN related problems. Has the engine control module (ECM) stored any diagnostic trouble code (DTC) indicating this? Fault-trace and remedy these diagnostic trouble codes (DTCs) first.

Are any CAN related diagnostic trouble codes (DTC) stored in the engine control module (ECM)?
Yes - Testing Complete.
No - Continue below.


Status check
Check to see is the fault is intermittent or permanent.
- Start the engine.
- Press the accelerator pedal (AP) down at the same time as the brake pedal is despressed.

The fault is intermittent if the engine speed (RPM) increases.

The fault is permanent if the engine speed (RPM) doe not increase.

Hint: Switch off the engine. Repeat the start procedure 3 times (to attempt to induce a permanent fault)

Is the fault permanent?
Yes - Continue below.
No - Testing Complete.


Checking the component
Check that there is voltage via the fuse for the stop lamp switch.

Check the signal cable between the brake light switch terminal #2 and engine control module (ECM) #B26. Check between engine control module (ECM) terminal #A38 and the throttle unit terminal #2. Check for a short-circuit to ground. Check for an open-circuit. Check for a short-circuit to supply voltage.

Remedy as necessary.

Other information:
- To fault-trace and check wiring and terminals, [1][2]Checking Wiring and Terminals

Was a fault detected?
Yes - Testing Complete.
No - Continue below.


Replacing the component
The engine control module (ECM) has registered an internal fault. Try a new engine control module (ECM).

Caution! A new control module is delivered without software. The control module must be programmed in order to function after replacement.