TM 5-3805-298-23-1
0064
Table 1. 1785 Intake Manifold Pressure Diagnostic Codes - Continued.
064
CID FMI CODE
TEST OR INSPECTION
CORRECTIVE ACTION
NOTE
1785-10 Intake Manifold
Pressure Sensor Signal
Always inspect wiring harness connectors that are involved in the circuit.
Abnormal Rate of Change
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 wiring 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 loss of the 5 Volt supply at the connector for the intake
manifold pressure sensor.
POSSIBLE CAUSE
Engine control wiring harness is high resistance or open.
Engine control wiring harness is shorted to ground.
Engine ECM.
Test Step 1. Check for Active
Diagnostic Codes.
Connect MSD. Select C6.6 924. Start
Diagnostic Code 1785-10 Active -
engine (TM 5-3805-298-10) and check Proceed to Test Step 2.
for active diagnostic codes (WP 0008). Diagnostic Code 1785-10 Not
Active - Troubleshooting is complete.
Test Step 2. Test 5 Volt Sensor
Supply and Ground Circuit Function.
1. Turn ignition switch and battery
disconnect switch to OFF position
(TM 5-3805-298-10).
2. Remove right engine access panel
(WP 0348).
3. Disconnect connector E-C8
(WP 0012, Figure 30) from intake
manifold pressure sensor.
4. Turn battery disconnect switch and
ignition switch to ON position
(TM 5-3805-298-10).
5. Using digital multimeter
Voltage Is 4.8 to 5.2 VDC - Proceed to
(WP 0174), test for voltage
step 6.
between connector E-C8
Voltage Is Less Than 4.8 VDC -
(WP 0012, Figure 30) terminal 1
Proceed to Test Step 3.
and ground.
