Table 1. 0548 Throttle Lock Diagnostic Codes.
TEST OR INSPECTION
0548-05 Throttle Lock Lamp
Current Below Normal
· Always inspect harness connectors that are involved in the circuit. Poor
connections can often be the cause of a problem in an electrical circuit.
Verify that all connections in the circuit are clean and secure and that all
connections are in good condition. If a problem with the connection is
found, correct the problem and verify that this malfunction or diagnostic
code is active before performing this procedure.
· Perform open or short-circuit test at each harness connection to identify
the correct harness to replace.
· Tag all wiring harnesses to aid in installation.
· Perform this test only if condition is active.
DIAGNOSTIC CODE SET CONDITION
Engine ECM Detects Abnormally Low Current on Throttle Lock Lamp Circuit
F707 During Lamp Test or Throttle Lock Operation.
· Throttle Lock LED Open.
· Dash Wiring Harness High Resistance or Open.
· Main Cab Wiring Harness High Resistance or Open.
· Engine Interface Wiring Harness High Resistance or Open.
· Engine ECM.