P1612
P1612 - MAXIMUM GOVERNOR SPEED DEVIATION - FUEL LIMITING
When Monitored and Set Condition
- When Monitored: Ignition on.
- Set Condition: Just after key on, the throttle is opened and closed to test the system. If the Throttle Position Sensor (TPS) does not quickly exceed a calibrated value this DTC will set. One trip fault.
Diagnostic Test
1. PRE-DIAGNOSTIC CHECK OUT
NOTE: Always perform diagnostics with a fully charged battery.
NOTE: Check connectors - Clean/repair as necessary. Poor pin to terminal connections can set DTCs.
NOTE: Check for applicable TSBs related to the problem.
Turn the ignition on.
With the DRB III(R), read PCM DTCs.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors. Repair as necessary.
Perform this procedure prior to symptom diagnosis.
Continue
- Go To 2
2. CHECK FOR CURRENT DTC
NOTE: If the PCM detects and stores a DTC, the PCM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the DRB III(R) at the same time the DTC is displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for an active DTC.
Turn the ignition on.
With the DRB III(R), erase PCM DTCs.
NOTE: It maybe necessary to road test the vehicle for this DTC to set.
With the DRB III(R), read PCM DTCs.
Did this DTC set again?
Yes
- Go To 3
No
- Go To 10
3. THROTTLE PLATE STUCK OPEN
Turn the ignition off.
Remove the Air Cleaner Housing and the MAF Sensor from the Throttle Body.
Check for any signs of a foreign material causing the throttle plate to remain open.
Manually open and close the throttle plate using your hands.
Does the Throttle Plate move?
Yes
- Go To 4
No
- Remove the debris if possible or replace the Throttle Body. Disconnect the Battery when replacing the Throttle Body.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2
4. THROTTLE CONTROL MOTOR 2 CIRCUIT SHORT TO VOLTAGE
With the ignition off.
Disconnect the PCM C1 harness connectors and the Throttle Body harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Turn the ignition on.
Measure the voltage of the Throttle Control Motor 2 circuit at the Throttle Body harness connector.
Is the voltage below 1.0 volt?
Yes
- Go To 5
No
- Repair the Throttle Control Motor 2 circuit for a short to voltage.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2
5. THROTTLE CONTROL MOTOR 1 CIRCUIT OPEN
Turn the ignition off.
Measure the resistance of the Throttle Control Motor 1 circuit from the Throttle Body harness connector to the PCM C1 harness connector.
Is the resistance below 5.0 ohms?
Yes
- Go To 6
No
- Repair the Throttle Control Motor 1 circuit for an open.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2
6. THROTTLE CONTROL MOTOR 2 CIRCUIT OPEN
With the ignition off.
Measure the resistance of the Throttle Control Motor 2 circuit from the Throttle Body harness connector to the PCM C1 harness connector.
Is the resistance below 5.0 ohms?
Yes
- Go To 7
No
- Repair the Throttle Control Motor 2 circuit for an open.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2
7. THROTTLE CONTROL MOTOR 1 CIRCUIT SHORTED TO GROUND
With the ignition off.
Measure the resistance between ground and the Throttle Control Motor 1 circuit at the PCM C1 harness connector.
Is the resistance above 100 kohms?
Yes
- Go To 8
No
- Repair the Throttle Control Motor 1 circuit for a short to ground.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2
8. THROTTLE CONTROL MOTOR 2 CIRCUIT SHORTED TO GROUND
With the ignition off.
Measure the resistance between ground and the Throttle Control Motor 2 circuit at the PCM C1 harness connector.
Is the resistance above 100 kohms?
Yes
- Go To 9
No
- Repair the Throttle Control Motor 2 circuit for a short to ground.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2
9. PCM
NOTE: Before continuing, check the PCM C1 harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.
If there are no possible causes remaining, view repair.
Repair
- Replace and program the Powertrain Control Module.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2
10. INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
NOTE: Check connectors - Clean/repair as necessary. Poor pin to terminal connections can set DTCs.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors specific to this DTC. Wiggle the wires while checking for shorts and open circuits.
NOTE: Check for any Technical Service Bulletins that may apply.
Were there any problems found?
Yes
- Repair as necessary.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2
No
- The condition that caused this DTC to set is currently not present. Inspect the related wiring harness for a possible intermittent condition.