MerCruiser 305 CID (5.0L) Service Manual page 689

DIAGNOSTICS
Code 22 (2 of 3): Throttle Position (TP) Sensor Circuit
Step
1.
2.
3.
4.
5.
6.
7.
8.
Index
Page 5G-62
Was the "On-Board Diagnostic" (OBD) System Check
Performed?
Are you using a Scan Tool?
a. Throttle closed.
b. Ignition OFF.
Does scan tool indicate TP sensor voltage less than
.30 volt?
a. Ignition OFF
b. Disconnect TP sensor harness connector.
c. Connect a jumper wire from harness terminal "A" CKT
416 to harness terminal "B" CKT 417.
d. Ignition ON, engine OFF.
Does scan tool indicate TP sensor voltage greater
than 4 volts?
a. Ignition OFF.
b. Connect DVOM from harness terminal "A" (CKT 416) to
a known good ground.
Does scan tool indicate TP sensor voltage greater
than the specified value?
Trouble code 22 is intermittent. Locate and repair inter-
mittent faulty connections. Refer to "Diagnostic Aids."
a. Switch CodeMate Tester to the normal mode.
b. Ignition OFF.
c. Disconnect throttle sensor harness connector.
d. Connect a jumper wire form harness terminal "A" CKT
416 to harness terminal "C" CKT 417.
e. Start engine and idle for 2 minutes or until CodeMate
Tester indicates a stored trouble code, whichever oc-
curs first.
f. Ignition ON, engine OFF.
g. Switch CodeMate Tester to "Service Mode" and note
trouble code.
Is trouble code 21 present?
a. Remove jumper wire from CKT 416 and CKT 417.
b. Connect DVOM from harness terminal "A" CKT 416 to
harness terminal "B" CKT 813.
Is voltage reading above 4 volts?
Action
SERVICE MANUAL NUMBER 24
Yes No
PROCEED TO
Step 2. OBD
Step 3. Step 7.
Step 4. Step 6.
Step 9. Step 5.
Step 10. Step 11.
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Step 9. Step 10.
Step 10. Step 11.
90-861327--1 OCTOBER 1999