F97068 2 Mercury THERMOSTAT (130 DEGREES)

Table 1
Diagnostic Conditions and the Combinations of Cylinders that are Affected    
Condition     Cylinders    
Circuit driver's side open     Only one cylinder is affected.    
Return side open    
Return side short to ground    
Circuit driver's side short to +battery for cylinders 1, 2, 7, 8, 9, 10, 11, 12, 17, 18, 19, or 20
   
Circuit driver's side short to ground for cylinders 1, 2, 7, 8, 9, 10, 11, 12, 17, 18, 19, or 20
   
Return side short to +battery for cylinders 5, 6, 13, or 14    
Cylinder 3 or 5
Circuit driver's side short to +battery     3 and 5    
Cylinder 4 or 6
Circuit driver's side short to +battery     4 and 6    
Cylinder 13 or 15
Circuit driver's side short to +battery     13 and 15    
Cylinder 14 or 16
Circuit driver's side short to +battery     14 and 16    
Return side short to +battery     1, 3, 7, and 9    
11, 15, 17, and 19
2, 4, 8, and 10
12, 16, 18, and 20 Because the circuits are in pairs or groups, multiple diagnostic codes can be activated for a single problem. If multiple diagnostic codes are active for the primary ignition, troubleshooting the circuits one at a time is an effective way to find the root cause.Logged diagnostic codes provide a historical record. Before you begin this procedure, use the Caterpillar Electronic Technician (ET) to print the logged codes to a file.The most likely causes of the diagnostic code are a poor electrical connection or a problem in a wiring harness. The next likely cause is a problem with an ignition transformer. The least likely cause is a problem with an ECM.
Illustration 1 g00994995
Schematic for the primary ignition on the left side of the engine
Illustration 2 g00903796
Schematic for the primary ignition on the right side of the engineTest Step 1. Inspect the Electrical Connectors and Wiring
Set the engine control to the OFF/RESET mode. Switch the 16 amp circuit breaker OFF.Note: For the following steps, refer to Troubleshooting, "Inspecting Electrical Connectors".
Illustration 3 g00903975
Terminal box for the master ECM (1) J2/P2 connectors for the master ECM (2) 16 amp circuit breaker
Illustration 4 g00903988
Terminal box for the slave ECM (3) J4/P4 connector for the slave ECM
Thoroughly inspect the following connectors:
Master ECM J2/P2 connectors
J4/P4 connectors for the slave ECM
Check the torque of the Allen head screw for the ECM connectors. The proper torque is 6 1 N m (55 9 lb in).
Illustration 5 g00995001
Harness side of the master ECM P2 connector (P2-1) Number 2 transformer's circuit driver (P2-2) Number 2 transformer's return (P2-3) Number 12 transformer's circuit driver (P2-4) Number 12 transformer's return (P2-14) Number 4 transformer's circuit driver (P2-15) Number 4 transformer's return (P2-16) Number 16 transformer's circuit driver (P2-17) Number 16 transformer's return (P2-24) Number 8 transformer's circuit driver (P2-25) Number 8 transformer's return (P2-26) Number 20 transformer's circuit driver (P2-27) Number 20 transformer's return (P2-32) Number 10 transformer's circuit driver (P2-33) Number 10 transformer's return (P2-34) Number 18 transformer's circuit driver (P2-35) Number 18 transformer's return (P2-48) Number 6 transformer's circuit driver (P2-49) Number 6 transformer's return (P2-50) Number 14 transformer's circuit driver (P2-51) Number 14 transformer's return