Honda BF135A - Ckp Sensor Troubleshooting

5-30
BF135A•BF150A
6. MAP sensor signal line open circuit check
-1. Turn the ignition switch OFF and disconnect the ECM
connector B.
-2. Check for the continuity between the No. 2 (White/Red)
terminal of the MAP sensor harness side 3P connec-
tor and the No. 5 (White/Red) terminal of the ECM con-
nector B.
Is there the continuity?
YES – Perform “7. MAP sensor check”.
NO – Repair open in the wire between the MAP
sensor and ECM.
7. MAP sensor check
-1. Connect the ECM connector B and the MAP sensor
3P connector.
-2. Turn the ignition switch ON and read the PB voltage
using the HDS pocket tester.
Is the voltage 2.76 – 2.96V?
YES – Substitute a known-good ECM and recheck.
NO – Replace the MAP sensor.
• CKP Sensor Troubleshooting
DTC 4-1: No CKP pulse
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. Start the engine and let it run at idling under no load.
-3. Check the DTC using the HDS pocket tester.
Does the DTC 4-1 appear?
YES – Perform “2. CKP sensor power line check”.
NO – Temporary failure (Disappeared)
2. CKP sensor power line check
-1. Turn the ignition switch OFF and disconnect the CKP
sensor 3P connector.
-2. Turn the ignition switch ON. Measure the voltage
between the No. 1 (Yellow/Black) terminal and the No.
2 (Green/Red) terminal of the CKP sensor harness
side connector.
Is there the battery voltage?
YES – Perform “4. CKP sensor signal line open cir-
cuit check”.
NO – Perform “3. CKP sensor power line open cir-
cuit check”.
ECM CONNECTOR B
MAP SENSOR
HARNESS SIDE
3P CONNECTOR
PB
(WHITE/RED)
VIEWED FROM THE
TERMINAL SIDE
CKP SENSOR HARNESS
SIDE 3P CONNECTOR
LG1
(GREEN/RED)
IGP
(YELLOW/BLACK)
VIEWED FROM THE
TERMINAL SIDE