Tp Sensor Troubleshooting - Honda BF135A Manual

BF135A•BF150A
Is the measurement 4.30 – 5.25V?
YES – Repair open in the sensor ground line.
NO – Repair open in the wire between the ECM
and the ECT sensor 1.
4. ECT sensor 1 check
-1. Turn the ignition switch OFF and connect the HDS
pocket tester.
-2. Turn the ignition switch ON and check the engine
coolant temperature with the HDS pocket tester.
Is the engine coolant temperature normal?
YES – Substitute a known-good ECM and recheck.
NO – Replace the ECT sensor 1 and recheck.

• TP Sensor Troubleshooting

DTC 7-1: TP sensor voltage is low
1. Symptom reproduction test
-1. Connect the HDS pocket tester and clear the DTC
once. If the DTC can not be cleared, go on the trou-
bleshooting.
-2. Turn the ignition switch ON.
-3. Measure the TP sensor voltage using the HDS pocket
tester.
Is the measurement 0.08 – 4.92V?
YES – Temporary failure (Disappeared)
NO – Perform "2. TP sensor signal line short circuit
check".
2. TP sensor signal line short circuit check
-1. Turn the ignition switch OFF and disconnect the TP
sensor connector.
-2. Disconnect the ECM connector B.
-3. Check for continuity between the No. 2 (Red/Black) ter-
minal of the TP sensor harness side 3P connector and
the engine ground.
TP SENSOR HARNESS
SIDE 3P CONNECTOR
VIEWED FROM THE
TERMINAL SIDE
Is there the continuity?
YES – Repair short in the wire between the TP sen-
sor and the ECM.
NO – Perform "3. TP sensor check".
3. TP sensor check
-1. Connect the ECM connector B and the TP sensor 3P
connector.
-2. Turn the ignition switch ON and measure the TP sen-
sor voltage using the HDS pocket tester.
Is the measurement voltage 4.49 – 4.85V at full
open throttle and 0.44 – 0.56V at full close throttle?
YES – Substitute a known-good ECM and recheck.
NO – Replace the TP sensor.
THL (RED/BLACK)
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