Table 1. Transmission Code (0573-03 to 0967-09) Troubleshooting Procedures - Continued.
CDI FMI CODE
TEST OR INSPECTION
0621-03 Downshift Switch
Voltage Above Normal
ECM will log a diagnostic code.
N OT E
Always inspect the harness connectorsthat 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 a con-
nection is found, correct the problem and verify that this diagnostic code
is Active before performing this procedure.
Perform open or short circuit test ateach harness connection to identify
correct harness to replace.
Perform this test only if condition is active.
Test Step 1. Verify if Code 0621-03
0621-03 Code Active - Proceed to
Trans/Chassis 120M and verify
Test Step 2.
0621-03 is active.
0621-03 Code Not Active - Trouble-
Test Step 2. Test Downshift Switch
1. Turn ignition switch and battery
disconnect switch to the OFF
position (TM 5-3805-293-10).
2. Disconnect harness connector
from transmission ECM J1 (WP
N OT E
Harness connector is located behind cab bulkhead cover on right rear
3. Remove rear bulkhead cover
plate (WP 0266).
4. Disconnect rear chassis wiring
harness connector FA-C22 (WP
0009, Figure 47) from cab lower
wiring harness connector P-C69
5. Install a jumper wire between har-
ness connector FA-C22 (WP
0009, Figure 47) terminal 52 and