Troubleshooting Guide — 18 Surges While Cruising
F2-50flowchart18 SURGES WHILE CRUISING
DESCRIPTION: Unexpected change in engine speed that is usually repetitive
NOTE
[TROUBLESHOOTING HINTS]
1. Air/fuel mixture too lean
2. Misfire
3. Poor connection in wiring harness
18 Surges While Cruising
1
STEP 1: Is "00" displayed on SST with ignition switch ON? (page F2-73)
No
Diagnostic trouble code No. displayed — Check for cause (Refer to specified check sequence) (page F2-74)
Yes
2
"00" displayed — Go to next step
3
STEP 2: Does SST Monitor Light show that switches operate correctly with ignition switch ON? (page F2-92)
No
Light does not turn ON or OFF with specified input switch — Check for cause (Refer to specified check sequence) (page F2-93)
No
Light always ON — Check ECM terminal 1D voltage (page F2-141)
Yes
4
Go to next step
5
STEP 3: Is throttle position sensor OK? (page F2-150)
No
Adjust (page F2-151)
Yes
6
Go to next step
7
STEP 4: Disconnect heated oxygen sensor connector; does condition improve?
Yes
Check heated oxygen sensor (page F2-154)
No
8
Go to next step
9
STEP 5: Are ECM terminal 2C and 2D voltages OK? (page F2-141)
No
Check for cause (page F2-141)
Yes
10
Go to next step