Table 1. 0590 Communication Diagnostic Codes Continued.
TEST OR INSPECTION
10. If lowered, install left frame access
0590-09 Engine Control
plate (WP 0376).
Module Abnormal Update
12. Troubleshooting complete.
0590-12 Wrong Response
From Engine Control
· 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 Fails to Communicate with Transmission/Chassis ECM.
· Circuit Breaker F14 Open.
· Engine Interface Wiring Harness High Resistance, Open, or Shorted.
· Main Cab Wiring Harness High Resistance, Open, or Shorted.
· Fuse Panel Wiring Harness High Resistance, Open, or Shorted.
· Basic Engine Wiring Harness Shorted.
· Circuit Breaker Panel.
· Engine ECM Software Incorrect or Requires Updating.
· Engine ECM.
· Transmission/Chassis ECM Software Incorrect or Requires Updating.
· Transmission/Chassis ECM.
Test Step 1. Verify if Engine ECM
Communicates with ET.
1. Turn battery disconnect switch and
ignition switch to ON position
2. At MSD, select C15 620
ECM Communicates Proceed to
Test Step 2.
ECM Fails to Communicate Proceed
to Test Step 5.