H - Fuel Control

Enter this Pinpoint Test only when service code 41 or 42 is received during Quick Test or you have been directed here by Quick Test step 9.0 (Diagnosis By Symptom) or Pinpoint Test S.

NOTE: Engine oil contaminated with fuel may affect service codes 41 and 42. If this condition is suspected, remove PCV from valve cover and rerun Quick Test. If the problem is corrected, change engine oil and filter.

This Pinpoint Test is only intended to diagnose the following:

1. HEGO (oxygen) sensor.
2. HEGO signal and ground circuit.
3. HEGO sensor connection.
4. Vacuum systems.
5. Fuel injectors.
6. ECA computer processor.
7. Harness circuits: HEGO GRD, HEGO, INJ. 1-6, VPWR, SIG RTN.

To prevent replacement of good components, be aware that these non-EEC areas may be faulty:

1. Ignition coil.
2. Fouled spark plugs.
3. Spark plug wires.
4. CANP problems.
5. PCV problems.
6. Distributorless ignition system.


PINPOINT TEST H SCHEMATIC

Pinpoint Test H Schematic:

TEST STEP H1

Test Step H1:

TEST STEPS H2 - H3

Test Steps H2 - H3:

TEST STEP H4

Test Step H4:

TEST STEPS H5 - H6

Test Steps H5 - H6:

TEST STEPS H7 - H8

Test Steps H7 - H8:

TEST STEP H11

Test Step H11:

TEST STEP H14

Test Step H14:

TEST STEP H15

Test Step H15:

TEST STEPS H16 - H17

Test Steps H16 - H17:

TEST STEP H20

Test Step H20:

TEST STEPS H21 - H22

Test Steps H21 - H22:

TEST STEP H23

Test Step H23:

TEST STEPS H24 - H25

Test Steps H24 - H25:

TEST STEP H28

Test Step H28:

TEST STEP H29

Test Step H29:

TEST STEP H30

Test Step H30: