Honda GL1800 Service Manual page 152

6. TP Sensor Harness Short Circuit Inspection
Check for continuity between the following wire
terminal and ground at the wire harness side TP
sensor 3P connector.
• Yellow/red
• Green/red
• Light green
Is there continuity?
YES – Short circuit in the following wires of
the engine sub-wire harness:
– Yellow/red
– Green/red
– Light green
NO – GO TO STEP 7.
7. TP Sensor Voltage at ECM
Connect the TP sensor 3P connector and engine
sub-wire harness 8P connector.
Install the air cleaner housing (page 5-57).
Connect the test harness set to the ECM connec-
tors (page 5-11).
Turn the ignition switch to "ON."
Measure the voltage at the test pin box
terminals.
Connection: No. 51 (+) – No. 8 (–)
Standard:
*0.4 – 0.6 V (throttle fully closed)
*4.2 – 4.8 V (throttle fully open)
• A voltage marked * refers to the value when
the input voltage reading (page 5-19) shows
5 V.
If the reading shows other than 5 V, derive a
voltage range at the test harness as follows:
Example:
In the case of a input voltage of 4.75 V:
0.4 x 4.75/5.0 = 0.38 V
0.6 x 4.75/5.0 = 0.57 V
Thus, the valid range is "0.38 – 0.57 V" for
throttle fully closed.
Replace this calculation using 4.2 and 4.8 to
get the resulting range for the throttle fully
open.
Is voltage within standard value?
NO – Faulty TP sensor.
YES – GO TO STEP 8.
8. TP Sensor Connection Inspection
Turn the ignition switch to "OFF."
Remove the test harnesses and connect the ECM
connectors.
Place the motorcycle on its side stand.
Turn the ignition switch to "ON."
Check that the MIL blinks.
Is the MIL blinking?
NO – Temporary failure;
normal.
YES – Replace the ECM with a new one and
inspect again.
FUEL SYSTEM (Programmed Fuel Injection)
No. 8 (–)
No. 51 (+)
the system is
5-21