"C28" STV ACTUATOR CIRCUIT MALFUNCTION
DETECTED CONDITION
The operation voltage does not reach the STVA.
ECM does not receive communication signal from
the STVA.
INSPECTION
Step 1
1) Remove the fuel tank and air cleaner box. ("5-15)
2) Turn the ignition switch OFF.
3) Check the STVA coupler for loose or poor contacts.
4) Turn the ignition switch ON to check the STV operation.
STV operating order: Full open A → Open B
(Approx. 1 seconds later)
Is the operation OK?
YES
Go to Step 2
• Loose or poor contacts on the STVA coupler.
NO
• Open or short circuit in the B/R and R/B wires.
Step 2
1) Turn the ignition switch OFF.
2) Check the STVA coupler for loose or poor contacts.
3) Disconnect the STVA coupler.
4) Check the continuity between terminal 1 and ground.
% STVA continuity: ∞ Ω (Infinity)
5) If OK, then measure the STVA resistance.
% STVA resistance: Approx. 7 – 14 Ω
! 09900-25008: Multi circuit tester set
' Tester knob indication: Resistance (Ω)
Is the resistance OK?
• Loose or poor contacts on the STVA coupler, or
poor J or L connection.
• If wire and connection are OK, intermittent trou-
YES
ble or faulty ECM. Recheck each terminal and
wire harness for open circuit and poor connec-
tion.
NO
Replace the STVA with a new one.
POSSIBLE CAUSE
• STVA malfunction.
• STVA circuit open or short.
• STVA motor malfunction.
1
2
2
FI SYSTEM DIAGNOSIS
4-37