P0024 Code: "B" Camshaft Timing Over-Advanced or Performance (Bank 2)
The bank 2 exhaust cam stays too far advanced or reacts too slowly; check the valve, the oil and the phaser.
At a glance
Severity: Moderate
- Meaning
- "B" Camshaft Timing Over-Advanced or Performance (Bank 2)
- System
- Fuel & Air Metering · Powertrain
- Safe to drive?
- With caution
- Typical repair cost
- $0–$2,500
- DIY difficulty
- Moderate
P0024 is the exhaust cam fault for bank 2 and only appears on V or boxer engines that phase the exhaust camshafts as well as the intakes. Like P0014 on bank 1, it means the exhaust cam stays closer to its fully advanced resting position than the PCM wants, or moves there and back too slowly. Because bank 1 carries an identical system, the fastest diagnosis compares the two banks and swaps parts between them. A few causes are more typical of bank 2: on many transverse V6 engines this valve sits on the rear head near the exhaust crossover, where heat bakes the oil into varnish, and as the hardest valve to reach it's the one most often disturbed or reconnected wrongly during other work. If P0021 and P0024 appeared together right after a repair, check first that the bank 2 intake and exhaust connectors weren't swapped.
Can I keep driving? Usually safe to drive for now; you may notice a slightly rough idle and a small loss of power. Have it checked promptly if a startup rattle develops, and keep an eye on the oil level in the meantime.
How to read P0024
- P Powertrain
- 0 Generic (SAE)
- 0 Fuel/air & emissions (aux.)
- 24 Specific fault
Symptoms
- Check engine light with slightly reduced mid-range power
- Idle a little less even than usual
- Higher fuel consumption on longer trips
- P0021 and P0024 together shortly after a repair, pointing at swapped connectors
- Short rattle from the bank 2 end of the engine on cold starts
Possible causes
Ranked by how often each cause is behind this code (editorial estimate).
- Bank 2 exhaust oil control valve varnished or sticking from heat
- Oil low, overdue or the wrong viscosity (look for P0014 as well)
- Bank 2 exhaust phaser worn: weak lock pin, broken return spring or leaking vanes
- Bank 2 intake and exhaust valve connectors swapped after a repair
- Chain or tensioner wear on the bank 2 side
- Bank 2 exhaust cam sensor or tone wheel giving an unsteady signal
Diagnosis step by step
After any repair, check for swapped plugs first
If the car recently had plenum, valve cover or spark plug work, confirm each bank 2 valve is plugged into its own connector. Swapped plugs make both cams do the wrong thing and typically set intake and exhaust codes on that bank at the same time.
Tools: Flashlight
Compare the two exhaust cams
Record desired and actual exhaust cam angle for both banks during a road test. If bank 1 follows its target while bank 2 lags or hangs near its base position, the fault is on bank 2.
Tools: OBD-II scanner
Swap exhaust valves between banks
If both exhaust control valves are interchangeable, swap them and clear the codes. A P0014 that appears afterwards condemns the valve you moved to bank 1.
Tools: Screwdriver, OBD-II scanner
Clean or replace the bank 2 exhaust valve
Pull the valve and look for heat varnish on the spool and debris in the screen. Replace it if the spool doesn't move crisply under brief 12-volt taps.
Tools: Screwdriver, Multimeter
Check the oil and listen to the phaser
Correct any oil level or grade problem, then listen for a rattle at cold start. A phaser that rattles and responds slowly with a good valve fitted needs replacing.
Tools: Flashlight, OBD-II scanner
Check the exhaust cam signal
If the actual angle jumps around rather than lagging smoothly, check the bank 2 exhaust cam sensor, its connector and the tone wheel before blaming the phaser.
Tools: Multimeter, OBD-II scanner
Where the parts are
- 1Ignition coil
- 2Spark plug
- 3Fuel injector
- 4Camshaft sensor
- 5Crankshaft sensor
- 6Engine computer (ECM)
- 7Intake manifold
Repair options & costs
| Repair | DIY? | Estimated cost |
|---|---|---|
| Correct swapped valve connectors | Yes | $0–$120 |
| Oil and filter change with the specified oil | Yes | $50–$120 |
| Replace bank 2 exhaust oil control valve | No | $120–$400 |
| Replace bank 2 exhaust cam phaser | No | $800–$1,800 |
| Bank 2 timing chain, guides and tensioner | No | $1,200–$2,500 |
Rough US estimates for parts and labor; shop rates vary by region. Not a quote.
Notes by brand
Field data
| Chevrolet | 8 | Traverse, Camaro Zl1, Colorado | |
|---|---|---|---|
| Hyundai | 5 | Santa Fe, Santa Fe Sport | |
| Kia | 4 | Sedona, Sorento |
Source: NHTSA Complaints API (US government open data), analyzed by DTC mention.
Emissions / smog test impact
Will fail
A state emissions test reads the PCM through the OBD-II port, and P0024 with the check engine light on is a fail. Repair it, then allow several days of driving so the readiness monitors complete before you return.
Frequently asked questions
Which camshaft is bank 2 "B"?
On a DOHC V engine, "B" is the exhaust camshaft and bank 2 is the bank without cylinder 1. So P0024 concerns the exhaust cam on the side opposite cylinder 1.
Both P0014 and P0024 are set. Where do I start?
With the oil. Two exhaust phasers misbehaving at once almost always share a cause such as low, old or wrong-grade oil. Change it, clear the codes and retest before buying valves.
Can swapped connectors really cause timing codes?
Yes. If the intake and exhaust valves on one bank use the same connector shape, the plugs can be swapped by mistake. The PCM then moves the wrong cam every time it commands one, and both cams miss their targets.
Why does replacing this valve cost more than the others?
On transverse V6 engines where bank 2 is the rear head, its exhaust side faces the firewall with the crossover pipe close by. Heat shields, the cowl panel or the intake plenum may have to come off, so labor is often higher than for the other three valves.
Sources
- SAE J2012 – Diagnostic Trouble Code Definitions
- ISO 15031-6 – Road vehicles, diagnostic trouble code definitions (EOBD)
- Manufacturer public service information (cross-checked)
- NHTSA Complaints API
- Methodology: How We Build Code Pages · Data Sources We Use · Editorial Policy