Hummer H1 Service Manual page 813

12-42 Electrical System
Step
19 Inspect the glow plug relay control circuit (CKT
466 YL) for a proper connection at the PCM and
replace the terminal if necessary.
Did you find an improper connection and make
the necessary repair?
20 Inspect the glow plug relay signal circuit (CKT
506 LB) for an open or short to ground. If the
glow plug relay signal circuit is open or shorted
to ground, repair as necessary.
Did you find and correct the condition?
21 Inspect the glow plug relay signal circuit (CKT
506 LB) for a proper connection at the PCM and
replace the terminal if necessary.
Did you find an improper connection and make
the necessary repair?
22 Test for a short to voltage in the glow plug relay
signal circuit (CKT 506 LB).
Did you find the improper condition?
23 Test for a short to voltage in the glow plug relay
control circuit (CKT 466 YL) .
Did you find and correct the condition?
24 Repair the open or poor connection on the battery
feed circuit.
Did you complete the repair?
25 Replace any glow plug that did not illuminate the
test lamp.
Did you complete the repair?
26 Repair the open or poor connections in the glow
plug harness.
Did you complete the repair?
27 Repair the short to ground in the glow plug har-
ness.
Did you complete the repair?
28 Replace the glow plug relay.
Did you complete the repair?
29 THE NEW PCM MUST BE PRO-
GRAMMED.Replace the PCM.
Did you complete the repair?
4-1-00
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Glow Plugs Inoperative (Cont'd)
Action Value Yes
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®
No
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