Actron CP9087 Service Manual page 40

Section 2
HIGH
LOW
POWER OFF
RANGE
VOLTS
OHMS
FREQUENCY
FUNCTION
TEST
2-32
Testing Sensors
11) Check MAP sensor power circuit.
Keep sensor connected to vehicle wiring.
• YELLOW test lead to sensor POWER circuit.
Use backprobe adapter.
• BLACK test lead to good vehicle GROUND.
• RANGE on HIGH.
• FUNCTION on VOLTS.
• Ignition key ON.
Good power circuit: Top (or next to top) TEST
light ON.
Go to next step.
Bad power circuit: TEST light OFF or not in top
(or next to top) position.
Repair open or short in power circuit wiring, then
retest.
12) Check MAP sensor ground circuit.
• Same set-up as previous step, but move
YELLOW test lead to sensor GROUND circuit.
(Use backprobe adapter.)
Good ground circuit: TEST light OFF.
Go to next step.
Bad ground circuit: Any TEST light ON.
Repair open in ground circuit wiring, then retest.
13) Check for connector problems.
• Ignition key OFF.
• Disconnect wiring harness from MAP sensor.
(Some vehicles use a metal snap ring to secure
wiring harness to sensor. Remove this snap ring
before disconnecting wiring harness.)
• Check terminals for damage, corrosion, bad
wire crimps or improper seating in connector.
Repair as necessary, then retest. If no trouble
found, go to next step.