Diagnostic System Check

Ensure battery condition, cold cranking amperage and reserve capacity meet specifications. Replace as necessary. Install scan tool. If scan tool powers up, go to next step. If scan tool does not power up, see SCAN TOOL DOES NOT POWER UP in BODY CONTROL MODULES - ELDORADO article in ACCESSORIES & EQUIPMENT.
Turn ignition on, engine off. Try to establish scan tool communication with Instrument Panel Cluster (IPC), Powertrain Control Module (PCM) and Body Control Module (BCM). If communication with each module is established, go to next step. If communication with any module is not established, see SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE in BODY CONTROL MODULES - ELDORADO article in ACCESSORIES & EQUIPMENT.
Select display DTC function for each module. Record all displayed DTCs, status of displayed DTCs and module that set the DTC. If DTCs are displayed, go to next step. If no DTCs are displayed, see ON-VEHICLE TESTING .

Retrieve codes and perform appropriate test. See DIAGNOSTIC TROUBLE CODE INDEX table.

DIAGNOSTIC TROUBLE CODE INDEX

DTC ⁽¹⁾

Description

Generator "L" Terminal Open Circuit

Generator "L" Terminal Problem

B1981, B1982 or B1983

⁽²⁾

B2710, B2711, B2719, B2750, B2780, B2781, B2782 or B2783

⁽³⁾

P0560, P0562, P0563, P0615, P0621 or P0622

⁽⁴⁾

⁽¹⁾	For any DTC beginning with the letter "U", see SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE in BODY CONTROL MODULES - ELDORADO article in ACCESSORIES & EQUIPMENT.

⁽²⁾	See BODY CONTROL MODULES - ELDORADO article in ACCESSORIES & EQUIPMENT.

⁽³⁾	See DIAGNOSTIC TESTS in ANTI-THEFT SYSTEMS - ELDORADO article in ACCESSORIES & EQUIPMENT.

⁽⁴⁾	See TROUBLE CODE DEFINITION table in SELF-DIAGNOSTICS - GASOLINE - 4.6L "E" & "K" BODIES article in ENGINE PERFORMANCE.