Holden Tx P1642 Engine Trouble Code
What is Holden Tx P1642?
Holden Tx P1642 indicates potential catalytic converter failure. If completely failed, your vehicle may not run properly and fuel economy will suffer significantly. Average replacement cost is $2,000–$2,140. This repair requires professional service and should not be delayed.
P1642 on the Holden Tx
In cold climates, Holden Tx vehicles frequently log P1642 during the first winter of ownership. Condensation inside the throttle body creates a temporary short circuit in the position sensor wiring, which clears once the engine warms up — but the fault code remains stored.
Code Information
| Code Type: | OBD-II Powertrain (P) Trouble Code |
| System: | Powertrain |
| Vehicle: | Holden Tx |
| Brand: | Holden |
| Model: | Tx |
| Code: | P1642 |
P1642 Holden Tx Symptoms
Check Engine Light
Illuminated Holden Tx dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration on the Holden Tx
Starting Problems
Difficulty starting the engine
Poor Fuel Economy
Increased fuel consumption on the Holden Tx
Increased Emissions
Failed emissions test due to P1642
P1642 Code Structure
Understanding what each digit means in the P1642 powertrain trouble code:
| P | 1 | 6 | 4 | 2 |
|---|---|---|---|---|
| Powertrain Code | Fuel And Air Metering | Fuel Temperature Sensor B Circuit Range/Performance | Injection Pump Fuel Metering Control 'B' High | Glow Plug/Heater Circuit 'A' Malfunction |
How to Fix Holden Tx P1642
Diagnostic Steps:
The catalytic converter has oxygen sensors before and after it. When warm and in closed-loop mode, the upstream O2 sensor reading should fluctuate, while downstream should remain steady.
Repair Solution:
Most manufacturers number cylinders sequentially from front to back. Ford V-engines start with cylinder 1 at front left. In V-6 engines, cylinder 4 is front right; in V-8 engines, cylinder 5 occupies that position.
Technical Notes:
For P1642, verify VCT solenoid operation. Look for stuck or sticking valves caused by contamination. Consult vehicle-specific repair manual for proper component testing procedures.
Holden Tx P1642 Repair Cost
PCV system overhaul on the Holden Tx — which resolves oil-mist contamination of the MAF sensor — costs $100–$200. The MAF sensor should be cleaned ($15–$25 DIY) or replaced ($80–$150) at the same time to ensure accurate fuelling after the fix.
P1642 Description
P1642 engine trouble code is related to Glow Plug/Heater Circuit 'A' Malfunction.
Main Cause
The primary reason for P1642 OBD-II Engine Trouble Code is: Fuel Temperature Sensor B Circuit Range/Performance.
Common P1642 Misdiagnosis on the Holden Tx
Fuel injector replacement is over-prescribed on the Holden Tx for P1642 when the actual fault is a weak fuel pump. Low fuel rail pressure causes lean misfire that looks identical to injector failure in static scan data without a live fuel pressure test.
DIY Repair Guide: P1642 on Holden Tx
When replacing sensors on the Holden Tx, always use anti-seize compound on the thread and dielectric grease on the electrical connector. This simple habit prevents the most common causes of sensor-related callbacks after repair.
Preventing P1642 on the Holden Tx
Inspecting the Holden Tx wiring harness conduit grommets annually — especially the floor pan grommet — costs nothing and takes 10 minutes. Catching moisture ingress early eliminates the most common electrical trigger for P1642 on this model.
Frequently Asked Questions — Holden Tx P1642
A: Yes. Some fault conditions, particularly those involving EVAP system leaks or marginal sensor readings, store codes without producing noticeable drivability symptoms. These are called memory faults and still need to be addressed because they will eventually cause performance issues.