Update, replaced several mass airflow sensor’s with no change. Still have the same code tripping after shifting into fourth gear the third time. Before that it says pending. I’m open to all suggestions

 

Update, I am unable to fix this code. Any other ideas? Truck runs fine and shifts fine.

 

Incorrect gear ratio 99.5% of the time is a bad transmission. Not sure why people think it is a MAF issue.

The terminology basically translates to human speak that the transmission sees an input shaft speed, and in gear 4 should correlate to a certain output shaft speed, and they do not line up.

you need a transmission.

DTC P0734
Gear ratio monitoring (4th gear).

Possible causes by suggested order of priority:
^ Output shaft signal not to specification.
^ Engine management ECM faults present.
^ Open circuit C243/E (K) to C193/42 (R).
^ Open circuit C243/F (B) to C193/14 (B).
^ Shaft speed electrical interference.
^ connectors C243,EAT C193.
^ Open circuit shaft speed sensorC193/14 (B) to C193/42 (R).
^ Shaft speed sensor fault.
^ Torque converter mechanical fault.
^ Gearbox mechanical fault.

Output Shaft Signal Not To Specification.
^ If using TestBook, the display shows the output shaft speed as measured by the transmission ECU and the engine speed as measured by the engine management ECM.
^ (If TestBook not available, use Live Data reading function on Scan Tool. [See Scan Tool manufacturers handbook for detailed instruction]).
CHECK THE FOLLOWING:
^ Check the gearbox specifications and ensure that the ratio of the engine speed against output shaft speed while in 4th gear is correct (drive vehicle on rolling road or road test).
^ At constant road speed with no gear changes both TestBook readings should be stable.
^ The two readings should also maintain the same ratio so long as no gear changes take place.
^ If the output shaft signal is unstable there may be a problem with the output shaft sensor circuit.
^ If the engine speed signal is unstable there may be a problem with the ECM or its sensors.
^ If the gear ratio is not to specification there may be a problem with the gearbox.
^ (If TestBook not available, use Live Data reading function on Scan Tool. [See Scan Tool manufacturers handbook for detailed instruction]).
POSSIBLE FAULTS
^ Output shaft sensor fault.
^ ECM or ECM sensors fault.
^ Gearbox mechanical fault.

Engine Management ECM Faults Present.
CHECK THE FOLLOWING:
^ Read ECM fault codes and check if any crankshaft sensor, engine speed, engine load/airflow or engine torque measurement faults are set.
^ Any faults present should be rectified.
POSSIBLE FAULTS
^ Faults set in ECM.

Open Circuit C243/E (K) To C193/42 (R).
CONNECTOR
^ Check for connector not correctly latched, backed out pins, damaged pins, corroded pins.

Open Circuit C243/F (B) To C193/14 (B).
OPEN_CIRCUIT
^ Check resistance > 1M Ohm

Shaft Speed Electrical Interference.
OPEN_CIRCUIT
^ Check resistance > 1M Ohm

Connectors C243,EAT C193.
OPEN_CIRCUIT
^ Check resistance > 1M Ohm

Open Circuit Shaft Speed SensorC193/14 (B) To C193/42 (R).
^ Use Live Data reading to display the output shaft speed as measured by the transmission ECU.
CHECK THE FOLLOWING:
^ With the engine running and the position switch in 'P' the shaft speed should measure 0 RPM.
^ If the reading is not 0 RPM then there may be a problem with electrical interference.
^ Check the connections to the screen around the output shaft sensor wiring.
POSSIBLE FAULTS
^ Faulty output shaft sensor wiring.
^ Faulty output shaft sensor.

Shaft Speed Sensor Fault.
^ Use Live Data reading to display the output shaft speed as measured by the transmission ECU.
CHECK THE FOLLOWING:
^ Monitor the road speed (from the vehicle speedometer) and the output shaft speed while driving on the road or on a rolling road.
^ The two readings should maintain the same ratio. If one reading doubles so should the other reading.
^ If the readings do not maintain a fixed ratio the output shaft sensor may be faulty.
POSSIBLE FAULTS
^ Faulty output shaft sensor

Torque Converter Mechanical Fault.
^ Use Live Data reading to display the output shaft speed as measured by the transmission ECU.
CHECK THE FOLLOWING:
^ Monitor the road speed (from the vehicle speedometer) and the output shaft speed while driving on the road or on a rolling road.
^ The two readings should maintain the same ratio. If one reading doubles so should the other reading.
^ If the readings maintain a fixed ratio the torque converter may be faulty.
POSSIBLE FAULTS
^ Transmission torque converter mechanical fault.

Gearbox Mechanical Fault.
CHECK THE FOLLOWING:
^ Ensure none of the electrical faults described in this section of the diagnostic are present.
^ Road test the vehicle. Ensure all gears are engaged during testing.
^ If the gearbox and vehicle behave abnormally there may be a mechanical problem with the gearbox.
POSSIBLE FAULTS
^ Gearbox mechanical fault.

 

Just returned from an eight hour trip mostly freeway driving. I’m not a transmission expert, but I do not believe the transmission was slipping at 70+ mph which would be fourth gear. If that’s the case I’ll drive it till it dies. Still doesn’t explain the black carbon on the tail pipe. It appears to me that it’s running rich. Not sure if it’s related to the code or not.

 

If you own a good running Land Rover with a LR V8 and the tailpipe doesn't have a black tip = it's probably not running. ALL LR V8's run rich no matter if it's a 3.5, 3.9, 4.0, 4.2, or 4.6.

Are all the clips and O-ring in place for your airbox/MAF?? I've worked on a few D2's with P0734 and it was a few things, low ATF, bad XYZ switch (ever have the M & S flash when it tosses the P0734?), and one was definitely a bad transmission/torque converter.

I also had an 02 Westminster for a short time that would not take off in D, but if you shifted manually thru the gears = drove perfect. It needed a new transmission, but zero fault codes if driven like a manual lol.

 

I appreciate the feedback and am considering all advice. Transmission appears to work fine, no lights or flashing. ATF checked and double checked. I’ve checked from air box to intake with new gaskets recently. Idles smooth and accelerates great. If it didn’t have the code, I would never know.

 

where is the shaft speed sensor or output shaft sensor located on 2003? How about the wires and harness?