Spectrum 3.0L GM - Page 215

215
DTC 522752 Start Failure Due to Cam Signal Error
Step Action Value(s) Yes No
1
 Did you perform the On-board diagnostics
(OBD) system check?
Go to step 2
Perform OBD
System check
2
 Check connections at C004, ECU-B pin M1,
M2, L1, and ECU-C pins A4 and F1.
Intermittent
problem. Go
to Preliminary
and Intermit-
tent Checks
Go to Step
(3)
3
 Key OFF, disconnect C004 Connector.
 Key ON, measure voltage across C004 pins
A and C.
Is voltage between 4.8 and 5.2 volts?
Between 4.8
and 5.2 volts
Go to Step
(4)
Go to Step
(5)
4
 Reconnect C004.
 Using suitable probe, back probe C004 pins
B and C.
 Connect a Multi-meter capable of measuring
Duty Cycle, + to pin B, - to pin C.
 Crank the engine.
Does the duty cycle read 90% (or 10%)? Duty
cycle can show either 90% or 10% ±5% depend-
ing on the meter.
Go to Step
(5)
Replace Cam
Sensor, Go to
Step (9)
5
 Wiring check
 Key OFF, disconnect ECU-C and C004
 Measure resistance from :
 C004 pin A to ECU-C pin A4
 C004 pin B to ECU-C pin F1
 C004 pin C to ECU-B pin M2
Is resistance less than 5?
<5
Go to Step
(6)
Repair the
circuit as ne-
cessary.
Refer to Wire
Harness
Repair. Go to
Step (9)
6
 Key OFF, disconnect ECU-C and C004
 Measure resistance from :
 C004 pin A to ground.
 C004 pin B to ground
 C004 pin C to ground
Is resistance greater than 30M?
>30M
Go to Step
(7)
Repair short
to ground as
necessary.
Refer to Wire
Harness
Repair. Go to
Step (9)
7
 Key OFF, disconnect ECU-C and C004
 Measure resistance from :
 C004 pin A to C004 pin B
 C004 pin A to C004 pin C
 C004 pin B to C004 pin C
Is resistance greater than 30M?
>30M
Go to Step
(8)
Repair short
in harness.
Refer to Wire
Harness re-
pair. Go to
Step (9)
8
 Replace ECU computer.
Is replacement completed?
Go to Step
(9)