Service manual

55
8/14/02
55
IDLE AIR CONTROL VALVE (IACV)
Fault Reported Possible Cause Action
Stepper motor fault
Damaged idle air control
valve, ECU, harness short or
open circuit, IACV connector
disconnected or damaged
Component test the IACV. Refer to "Idle
Air Control Valve (IACV)" starting on
page 55.
Check that harness connector is secure.
Disconnect ECU and go to Test 1.
Pinpoint Tests
Test Result Action
1. Check wire and terminal
integrity:
- P1 E1
- P1 E2
- P1 F1
- P1 F2
OK Go to Test 2.
Faulty
Locate and correct wiring fault and go to
Test 5.
2. Check resistance:
- P1 E1 to P1 F1
- P1 E2 to P1 F2
53
± 10% Ohms
Disconnect the IAVC and go to Test 3.
Open circuit Go to Test 4.
Short circuit Disconnect IACV and go to Test 5.
3. Check cable for short circuit:
- P1 E1 to ground
- P1 E2 to ground
- P1 F1 to ground
- P1 F2 to ground
OK Go to Test 7.
Short circuit
Locate and correct wiring fault and go to
Test 7.
4. Check cable continuity:
- P1 E1 to CN25 pin A
- P1 E2 to CN25 pin B
- P1 F1 to CN25 pin C
- P1 F2 to CN25 pin D
OK Go to Test 6.
Open circuit
Locate and correct wiring fault and go to
Test 7.
5. Check cable for short circuit:
- P1 E1 to P1 F1
- P1 E2 to P1 F2
OK Go to Test 6.
Short circuit
Locate and correct wiring fault and go to
Test 7.
Check IACV resistance:
- IACV pin A to pin D
- IACV pin B to pin C
53
± 10%
Go to Test 7.
Faulty Replace IACV, go to Test 7.
7. Reconnect harness, run
engine and check for presence
of fault.
OK Done
Fault still present Contact Cannondale Dealer Service.
Circuit Diagram