P2610-PCM INTERNAL SHUTDOWN TIMER RATIONALITY TOO FAST
P2610-PCM INTERNAL SHUTDOWN TIMER RATIONALITY TOO FAST
For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation
The Powertrain Control Module (PCM) compares actual shutdown time to a calculated shutdown time value. The calculated shut down time value is based on the amount of shutdown time necessary for the ECT to drop a specific amount after a completely warmed up engine is shut down. If the difference between actual shutdown time and the calculated shut down time is greater than a maximum value, a one trip failure will set. The shutdown time is measured again after one hour of ignition off time following the next engine warm up cycle. The PCM compares the shutdown time to a calculated value. If the difference is greater than a maximum value, the MIL is illuminated and a DTC will set.
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When Monitored:
With the engine running after a cycle when a complete engine warm up was achieved, the difference between engine coolant temperature and ambient air temperature greater than 10°C (50°F), after a minimum temperature drop of 10°C (50°F) during ignition off and battery voltage greater than 10.0 Volts.
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Set Condition:
The Powertrain Control Module (PCM) detects that the engine coolant temperature drops a specified amount during the measured engine off time. Two trip fault. Three good trips to turn off the MIL.
Possible Causes |
|---|
| POWERTRAIN CONTROL MODULE (PCM) SOFTWARE UPDATE |
| EXCESSIVE RESISTANCE IN THE PCM POWER OR GROUND CIRCUITS |
| POWERTRAIN CONTROL MODULE (PCM) |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
| NOTE: | Diagnose and repair any other DTCs set in the PCM before proceeding with this test. |
| 1. | Turn the ignition on. |
| 2. | With the scan tool, clear DTCs in the Powertrain Control Module (PCM). |
| 3. | Start the engine and allow it to reach operating temperature. |
When the engine is operating, do
not stand in direct line with the fan. Do not put your hands near
the pulleys, belts or fan. Do not wear loose clothing. Failure to
follow these instructions may result in possible serious or fatal
injury.
WARNING:
| 4. | With the scan tool, select View DTCs. |
Is the DTC Active at this time?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
2. CHECK THE (F202) FUSED IGNITION SWITCH CIRCUIT
 |
| 1. | Turn the ignition off. |
| 2. | Disconnect the PCM C1 harness connector. |
| 3. | With a 12-Volt test light connected to ground, probe the (F202) Fused Ignition Switch circuit. |
| 4. | Perform the above check with the Ignition key in the off lock position, Ignition on, engine not running position and during cranking. |
| 5. | Wiggle the related wire harness while probing the special tool with the test light to try to interrupt the circuit. |
Does the test light illuminate brightly?
Yes
- Go To 4
No
- Repair the open or excessive resistance in the (F202) Fused Ignition Switch (Off, Run, Start) circuit. Inspect the related fuse, if the fuse is open check the circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
3. CHECK THE (Z921) GROUND CIRCUITS
 |
| 1. | Turn the ignition off. |
| 2. | With a 12-volt test light connected to 12 Volts, probe the (Z921) Ground circuits. |
| 3. | Wiggle the related wire harness while probing the special tool with the test light to try to interrupt the circuit. |
Does the test light illuminate brightly?
Yes
- Go To 4
No
- Repair the open or excessive resistance in the (Z921) Ground circuits. Inspect the related fuse, if the fuse is open check the circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
4. POWERTRAIN CONTROL MODULE (PCM)
| 1. | Verify that the PCM is operating at the latest software version available. |
| 2. | Perform any Technical Service Bulletins that may apply. |
Were any problems found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
- Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information. (Refer to 08 - Electrical/8E - Electronic Control Modules/MODULE, Powertrain Control - Removal) .
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).